JP4721117B2 - Wet paper smoothing method and paper machine press part - Google Patents

Description

  The present invention transfers the wet paper from the press part to the smoothing press roll that smoothes the wet paper by applying surface pressure from the final press for dehydration in the final step of the press part of the paper machine that pressurizes and dehydrates the wet paper. The present invention relates to a method and an apparatus capable of stably running the wet paper and preventing the wet paper from generating wrinkles during transfer.

The press part following the wire part of the paper machine passes through a smoothing press that pressurizes and dehydrates the wet paper with a multi-stage press unit with two sheets of felt sandwiched between the upper and lower sides and then smoothes the surface of the wet paper. After that, the wet paper is run in the drying process.
In recent years, the dewatering performance per press unit has been improved, so that the press unit is reduced to a single stage for the purpose of shortening the pressure dehydration process at the press part and simplifying the equipment. Tend to do.
Further, the pressure dehydration method in which the press units are arranged in multiple stages and the nip pressure is applied to the wet paper a plurality of times has been a problem in the production of bulky paper.

For example, Patent Document 1 (WO 2004/101885 A1) discloses a configuration from a press part constituted by a one-stage press unit to a dryer part, and this configuration is shown in FIG.
In FIG. 5, the wet paper web 01 that has passed through the former part (not shown) is sucked by the suction pick-up roll 05a and held by the felt 06a, and then sandwiched between the felt 06a and the felt 06b. It is conveyed to.

The final press for dehydration 04 includes a press roll (or shoe press) 04a and a press roll 04b, and the moisture contained in the wet paper 01 is moved to the felts 06a and 06b by the nip pressure of the press rolls 04a and 04b. We are letting you squeeze water. In addition, in the nip portions of the press rolls 04a and 04b, the moisture content in the wet paper 01 not only moves into the felts 06a and 06b due to the applied pressure, but also a splash s in which water scatters from the felt occurs.
Thus, the wet paper 01 having a water content of about 80 wt% at the inlets of the press rolls 04a and 04b is dehydrated to about 50 to 55 wt% at the outlets of the press rolls 04a and 04b.

  The wet paper 01 squeezed by the final dewatering press 04 is sucked by the suction roll 05b and carried on the felt 06b, and then passed through a pair of nip transfer rolls 011a and 011b. Pressure (5-20 KN / m) is applied. In the pair of nip transfer rolls 011a and 011b, a paper passing belt 013 made of an elastic member and having a smooth surface and no air permeability is nipped with the wet paper 01 and the felt 06b through the guide roll 019. When pressure is applied, the wet paper 01 sticks to the smoother surface and moves, so the wet paper 01 sticks to the paper passing belt 013 whose surface is smoother than that of the felt 06b, and the paper passing belt from above the felt 06b. Change the travel route to 013. The paper passing belt 013 may be made of a breathable felt as long as the surface is smoother than the felt 06b.

Thereafter, the wet paper 01 moves to the smoothing press 012, and surface pressure is applied at the nip portions of the smoother top roll 012 a and the smoother bottom roll 012 b while one side is supported on the paper passing belt 013, so Is smoothed. The smoothing press 012 is provided as a final press of the press part 02 of the paper machine. In this configuration, the smoothing press 012 is provided downstream of the final press 04 for dewatering in which the wet paper 01 is squeezed in the press part 02. .
Thereafter, the wet paper web 01 is transferred to the dryer part 03 via the canvas 07c, and the wet paper web 01 is dried through the first dryer 03a, the second dryer, and the third dryer (not shown) in this order. Reference numerals 020a and 020b in FIG. 5 are vacuum rolls.

  The felts 06a and 06b are endless, and after passing through the press rolls 04a and 04b, return to the upstream side and are circulated, but are washed with low-pressure shower water in a return path (not shown) and then returned to the return path. The contained water is sucked and dehydrated in the arranged suction box and reused for transporting wet paper.

WO2004 / 101885A1 publication

  In such a papermaking process, depending on the papermaking conditions (for example, basis weight, papermaking speed, etc.), as shown in FIG. 6, between the wet paper 01 and the felt 06b immediately upstream of the nip portion of the nip transfer rolls 011a and 011b. When the air reservoir k is generated and the air reservoir k is left as it is and is pressurized with the nip transfer rolls 011a and 011b, a paper-blowing phenomenon (blowing) in which the wet paper floats from the felt 06b occurs, and the paper is wrinkled. Were found by the present inventors.

  The cause of the air pool k is that after being pressurized and squeezed by the final depressing press 04 for dehydration, air is sucked into the breathable felt 06b when the pressurized state is released, and the air is sucked. When the felt 06 is pressurized by the nip transfer rolls 011a and 011b, the sucked air is discharged. A part of the air is accumulated between the felt 06b and the wet paper web 01 immediately upstream of the nip portion. A reservoir k is generated.

  When wrinkles enter the wet paper 01 in this way, the paper becomes defective and the running properties of the wet paper in the subsequent stage deteriorate. That is, if the wet paper 01 is transferred to the dryer part 03 in the state where wrinkles are generated, the running of the wet paper in the dryer part 03 is not stable, and the drying of the paper becomes uneven in the width direction of the paper. Arise.

  Conventionally, the wet paper 01 after exiting the transfer rolls 011a and 011b is adhered to the lower surface of the paper passing belt 013 and conveyed to the smoothing press 012. When the wet paper is transported from the nip transfer rolls 011a and 011b to the smoothing press rolls 012a and 012b, for example, when there is unevenness in the adsorption of the paper 01, the wet paper containing water is removed from the paper passing belt 013 by its own weight. It was found that they peeled off and sag downward m as shown in FIG. When this hanging portion is nipped by a smoothing press roll, there is a problem that wrinkles are generated on the wet paper at the nip portion.

  In the conventional press part shown in FIG. 5, the wet paper 01 is separated from the felt 06b at the exit of the nip transfer rolls 011a and 011b and transferred to the paper passing belt 013, and the wet paper 01 is carried on the paper belt 013. In this state, smoothing is performed by applying surface pressure with the smoothing press rolls 012a and 012b. At the exit of the nip portion of the smoother top roll 012a and the smoother bottom roll 012b, the wet paper 01 needs to be separated from the paper belt 013 and transferred to the surface of the smoothing press roll 012b.

For that purpose, when the nip pressure is applied, the wet paper 01 sticks to the smoother surface of the surface and moves, so that the surface smoothness of the paper passing belt 013 is made higher than the surface smoothness of the felt 06b, and The surface needs to be lower than the surface of the smoother bottom roll 012b, and the surface smoothness of the paper passing belt 013 is limited to a considerably restricted range. If the wet paper 01 is transferred to the paper passing belt 013 at the exits of the nip portions of the smoother top roll 012a and the smoother bottom roll 012b, there is a risk of paper breakage.
Here, A has a higher surface smoothness than B means that A has a smoother surface than B.

  The surface of the paper passing belt 013 is usually cleaned by a return path (not shown). The ease with which wet paper is attached differs depending on whether the surface of the paper passing belt is dry or wet. In addition, the operating environment of the paper machine is constantly changing, and the paper passing belt easily changes with time in the operating environment, and the surface smoothness varies with time.

  As described above, it is difficult to satisfy both the requirements of the wet paper attaching and peeling conflicting with the same paper passing belt. In addition, it is difficult to maintain the surface smoothness of the paper passing belt within the above-mentioned restricted range over a long period of time. There is a problem that running becomes unstable.

In view of the problems of the prior art, the present invention prevents the occurrence of defective products by preventing the occurrence of wrinkles due to the phenomenon of blowing (blowing) in the final step of the press part of the paper machine. The purpose is to stabilize the operation.
Another object of the present invention is to prevent the wet paper from dripping from the paper passing belt after leaving the transfer roll.
Further, another object of the present invention is that it is not necessary to maintain the surface smoothness of the paper passing belt in a restricted narrow range, and the surface of the smoother bottom roll (reference numeral 12b in FIG. 1) is passed through the paper passing belt (FIG. 1). Then, it is to be able to stabilize the running of the wet paper only by satisfying the condition that it should be smoother than 13).

In order to achieve this object, the first invention relating to the smoothing method of the present invention comprises:
In the wet paper smoothing method by the smoothing press, which is used as the final stage press of the paper machine press process and functions to smooth the surface of the running wet paper,
Separating the wet paper from the final press of the dewatering press of the paper machine in a state where both sides are supported by the felt by adsorbing the wet transfer paper to the suction transfer roll through the one felt; and
By passing the wet paper carried on the one felt through the first nip formed by the suction transfer roll and the first smoothing roll on the downstream side of the step, Transferring from a felt to a first smoothing roll;
And a step of performing a smoothing process through a wet paper to a second nip portion formed by the first smoothing roll and the second smoothing roll.

  In the press part following the wire part of the paper machine, a press process is performed in which the wet paper is pressure-dehydrated with at least a pair of press rolls. In the first invention according to the smoothing method of the present invention, The wet paper web that comes out of the final press roll of the dehydrating press while being supported on both sides by the felt is adsorbed to the suction transfer roll via the one felt to separate the wet paper web from the other felt.

  Thereafter, the wet paper adsorbed on the suction transfer roll through the one felt is transferred to the first smoothing roll by passing through the first nip portion, and the wet paper sticks to the first smoothing roll. In this state, a smoothing process is performed by applying a surface pressure to the second nip portion formed by the first smoothing roll and the second smoothing roll through wet paper through the nip portion. In the first nip portion, the wet paper can be transferred to the first smoothing roll by making the surface smoothness of the first smoothing roll higher than the felt.

  As described above, the present invention eliminates a pair of nip transfer rolls that apply a surface pressure in a state in which wet paper is sandwiched between a paper belt and felt as in the past on the upstream side of the smoothing press roll. The problem of air accumulation generated in the nip portion of the roll can be solved.

Further, since there is no running section of the wet paper carried on the lower surface of the paper passing belt between the transfer roll and the smoothing press roll, the above-mentioned problem of dripping does not occur.
Further, in order to transfer the wet paper from the felt to the first smoothing roll, there is only a restriction that the surface smoothness of the first smoothing roll is higher than that of the felt, and the same as in the conventional press part. It is not necessary to attach and peel the wet paper with the paper passing belt, and it is not necessary to maintain the surface smoothness of the paper passing belt within the above-mentioned restricted range for a long time. Since the surface smoothness of the felt is obviously clearly lower than that of the first smoothing roll, it is easy to satisfy such restrictions, and stable running of the wet paper becomes possible.

  For the evaluation of the surface smoothness, specifically, the surface roughness may be measured and compared. For example, by using a “stylus type surface roughness measuring device” described in JIS B 0651, JIS B 0633 According to “Product Geometric Specification (GPS) -Surface Properties: Contour Curve Method—Surface Property Evaluation Method and Procedure”, the surface roughness of both is compared, and the smoothness is determined to be low if the surface is rough. You may compare.

Next, the second invention according to the smoothing processing method of the present invention is as follows.
In the wet paper smoothing method by the smoothing press, which is used as the final stage press of the press section of the paper machine and functions to smooth the surface of the running wet paper,
Separating the wet paper from the final press of the dewatering press of the paper machine in a state where both sides are supported by the felt by adsorbing the wet transfer paper to the suction transfer roll through the one felt; and
By passing the wet paper carried on the one felt through a first nip formed by a nip roll and a first smoothing roll provided on the downstream side of the step, the wet paper Transferring from a felt to a first smoothing roll;
And a step of performing a smoothing process through a wet paper to a second nip portion formed by the first smoothing roll and the second smoothing roll.

  In the second invention, the difference from the first invention is that the wet paper discharged from the final press of the dewatering press of the paper machine is adsorbed to the suction transfer roll via the one felt from the other felt. A nip roll and a first smoothing roll provided on the downstream side of the suction transfer roll instead of the suction transfer roll and the first smoothing roll on the downstream side of the separating step It is in place to form with. The step of smoothing the wet paper that has exited the first nip with the first and second smoothing rolls is the same as the first configuration.

  When changing the nip pressure with the suction transfer roll, there is concern about the generation of suction marks on the paper, so the nip pressure cannot be changed freely. However, in the second configuration, a new nip roll is provided, Since the nip portion is formed between the nip roll and the first smoothing roll, the nip pressure can be made variable. For this reason, since it is not necessary to provide a nip function to the suction transfer roll, there is no concern about the occurrence of the suction mark.

  Further, if the nip roll is provided above the suction transfer roll, the wet paper web running path is arranged in the vertical direction in the wet paper web running section between the nip roll and the suction transfer roll. There is no risk of gravity in the direction of peeling.

The smoothing roll usually applies a surface pressure to the wet paper using a hard roll, but a soft cover may be attached to at least one of the smoothing rolls to ensure a nip width.
In the first invention or the second invention relating to the smoothing processing method, preferably, the second nip portion is subjected to a smoothing process through a paper passing belt together with a wet paper, and the paper passing belt includes The surface smoothness of the surface in contact with the wet paper is configured to be lower than the surface smoothness of the first smooth roll.

  Thus, the paper passing property can be improved by passing the paper passing belt together with the wet paper. If the elastic paper passing belt is passed, a necessary nip width can be secured. As a result, it is not necessary to attach a soft cover for securing the nip width to at least one of the smoothing rolls, and vibrations caused by unevenness of the surface of the soft cover during high speed operation do not occur. By making the surface smoothness of the paper passing belt lower than the surface smoothness of the smoothing roll, the wet paper is transferred to the surface of the first smoothing roll at the nip exit of the first and second smoothing rolls. Can be made easier.

In the conventional press part shown in FIG. 5, the surface smoothness of the paper passing belt has to be a limited range of surface smoothness that is higher than that of the felt and lower than that of the first smoothing roll. There has been a problem that the wet paper does not adhere to and peels off from the paper passing belt and the running of the wet paper becomes unstable. In the present invention, as described above, the surface smoothness of the paper passing belt is Since there is only a restriction of lowering the surface smoothness of one smoothing roll, it is easy to satisfy the restriction condition, and the problem that the running of the wet paper becomes unstable as in the prior art can be solved. it can.
Accordingly, there is an advantage that the allowable range of values that can be taken by the surface smoothness of the paper passing belt is widened, the degree of freedom of component selection at the time of replacing the paper passing belt is increased, and the life of the parts is extended by relaxing the restrictions.

  The smoother the paper passing belt, the worse the air permeability. In order to increase the surface smoothness of the wet paper, it is desirable to use a non-breathable belt. However, when the paper passing belt is made non-breathable, an air pool is generated immediately upstream of the second nip portion, and the paper blistering phenomenon in which the wet paper floats up from the first smoothing roll due to the air pool k. Since (blowing) occurs, it is necessary to provide a certain degree of air permeability to the paper passing belt. Therefore, if importance is attached to prevention of blowing, it is preferable to use a slightly air-permeable paper passing belt.

As an apparatus configuration for realizing the first aspect of the present invention relating to the smoothing processing method, the first aspect of the present invention relating to the press part,
In the press part of the paper machine provided with the smoothing press that is provided as the final stage press of the press part of the paper machine and functions to smooth the surface of the moving wet paper,
A suction transfer roll that separates the other felt from the wet paper by adsorbing the wet paper from the final press of the dewatering press of the paper machine while the both sides are supported by the felt through the one felt;
A first smoothing roll that forms a first nip portion with the suction transfer roll on the downstream side of the adsorption step to transfer the wet paper from the one felt;
A second smoothing process is performed by forming a second nip part with the first smoothing roll on the downstream side of the first nip part, and performing a smoothing process through wet paper through the second nip part. It is made up of a control roll.

In the first invention relating to the press part, the wet paper, which has come out from the final press roll of the dewatering press of the paper machine with both sides supported by felt, is adsorbed to the suction transfer roll via one felt. The other felt is separated from the wet paper.
Thereafter, a suction transfer roll and a first smoothing roll form a first nip portion on the flow side, a wet paper carried on a felt is passed through the first nip portion, and at the outlet of the first nip portion. The wet paper is separated from the felt and only the wet paper is transferred to the surface of the first smoothing roll.

In this case, the wet paper can be separated from the felt and transferred to the surface of the first smoothing roll by making the surface smoothness of the first smoothing roll higher than the felt.
Thereafter, the wet paper travels in a state of being attached to the first smoothing roll, and the second smoothing roll formed by the first smoothing roll and the second smoothing roll on the downstream side of the first nip portion. A smoothing process is performed by applying a surface pressure toward the nip portion and applying a surface pressure at the nip portion.
As described above, the first invention according to the smoothing processing method can be carried out by the first invention according to the press part, and the above-described operational effects of the first invention according to the smoothing processing method can be obtained. Can do.

Further, the second invention of the present invention related to the press part for carrying out the second invention of the present invention related to the smoothing processing method,
In the press part of the paper machine provided with the smoothing press that is provided as the final stage press of the press part of the paper machine and functions to smooth the surface of the moving wet paper,
A suction transfer roll that separates the other felt from the wet paper by adsorbing the wet paper from the final press of the dewatering press of the paper machine while the both sides are supported by the felt through the one felt;
A first smoothing roll provided on the downstream side of the suction transfer roll;
Forming a first nip portion with the first smoothing roll, and transferring the wet paper adsorbed by the suction transfer roll from the one felt to the first smoothing roll;
A second nip is formed between the first smoothing roll and the first smoothing roll on the downstream side of the first nip, and a smoothing process is performed by passing wet paper through the second nip. It is made up of a control roll.

  In the second invention relating to the press part, a first nip portion is formed by the first smoothing roll and the nip roll on the downstream side of the suction transfer roll, and the wet supported by the felt in the nip portion. By passing the paper, the wet paper is transferred to the surface of the first smoothing roll. After that, the smoothing process is performed through the second nip formed by the first and second smoothing rolls in the same manner as in the first invention.

  When changing the nip pressure with the suction transfer roll, there is concern about the generation of suction marks on the paper, so the nip pressure cannot be changed freely. However, in the second invention, an independent nip roll is provided. Can be made variable. In this configuration, since it is not necessary to use a nip roll as a suction roll, there is no concern about the occurrence of the suction mark.

  Further, as described above, if the nip roll is provided above the suction transfer roll, the wet paper web travel path is arranged in the vertical direction in the wet paper web travel section between the nip roll and the suction transfer roll. There is no risk of gravity in the direction of peeling the wet paper from the felt. Moreover, the wet paper web path of the press part can be shortened.

As described above, according to the second invention relating to the press part, the second invention relating to the smoothing processing method can be carried out, and the above-described operational effects of the second invention method can be obtained. it can.
In addition, it is preferable that the nip roll be a variable crown roll, so that the nip pressure can be freely controlled in the longitudinal axis direction of the roll.

  In the first and second inventions relating to the press part, preferably, the smoothing process is performed by passing the second nip portion together with the wet paper, and the surface smoothness of the surface in contact with the wet paper is the first. If a paper passing belt lower than the surface smoothness of the smoothing roll is provided, the wet paper passing property in the second nip portion is improved, and if an elastic paper passing belt is used, a necessary nip pressure is obtained. In addition, the above-described operational effects can be obtained.

  According to the first aspect of the present invention relating to the smoothing method and the press part, the wet paper web is transported to the first smoothing roll by felt, and the surface smoothness of the first smoothing roll is increased. Since it is easy to make it higher than the surface smoothness of the felt, the wet paper can be reliably transferred from the felt to the first smoothing roll, so that stable operation of the press part of the paper machine is possible.

Further, on the upstream side of the first and second smoothing rolls, the wet paper is carried from the felt to the paper passing belt by applying surface pressure while the wet paper is sandwiched between the paper belt and the felt as in the prior art. Does not require transfer roll.
Accordingly, the problem of air accumulation generated in the nip portion of the transfer roll is solved, and the running section of the wet paper carried on the paper passing belt is eliminated between the transfer roll and the smoothing press roll. Does not occur. Accordingly, there is no generation of wrinkles due to air accumulation or dripping of wet paper, and stable operation is possible. Moreover, the wet paper web path of the press part can be shortened.

According to the second aspect of the present invention relating to the smoothing method and the press part, in addition to the operational effects obtained in the first aspect, a nip roll is provided on the downstream side of the suction transfer roll, and the nip roll By forming the first nip portion with the first smoothing roll, the nip pressure of the first nip portion can be made variable.
Preferably, the nip roll is a variable crown roll so that the nip pressure can be freely controlled in the longitudinal axis direction or the circumferential direction of the roll.

Further, it is not necessary to attach and peel the wet paper with the same paper passing belt as in the prior art, and it is not necessary to maintain the surface smoothness of the paper passing belt within the above-mentioned restricted range for a long time. Therefore, the running of the wet paper does not become unstable depending on the operating state of the paper machine.
In addition, since the allowable range of values that the surface smoothness of the paper passing belt can take is widened, there is an advantage that the degree of freedom in selecting parts when replacing the paper passing belt is increased and the life of the parts is increased by relaxing the restrictions.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the present invention only to that unless otherwise specified.
FIG. 1 is a block diagram showing an embodiment (Embodiment 1) of the first invention of the present invention, FIG. 2 is a block diagram showing an embodiment (Embodiment 2) of the second invention of the present invention, and FIG. FIG. 4 is a vertical sectional view showing an example of a crown variable roll used in the second embodiment, and FIG. 4 is a cross-sectional view taken along the line AA in FIG.
(Embodiment 1)

  In FIG. 1 showing the first embodiment of the present invention, the wet paper 1 carried and transported on a wire 8 from a wire part (not shown) is sucked by a suction roll 5a and held on the felt 6a, and then felt 6a. And the felt 6b are conveyed to the final press 4 for dehydration while being sandwiched from both sides. The final press 4 for dehydration includes a shoe module 4a and a press bottom roll 4b, and the water contained in the wet paper 1 is moved to the felts 6a and 6b by these nip pressures to perform water extraction. In the figure, “a” indicates the conveyance direction of the wet paper web 1.

  The wet paper 1 squeezed by the final press 4 for dehydration is sandwiched between the felts 6 a and 6 b and conveyed to the suction transfer roll 21. In the suction transfer roll 21, the wet paper 1 is separated from the other felt 6 b by being adsorbed on the surface of the suction transfer roll 21 via the felt 6 a on one side.

Thereafter downstream, the suction transfer roll 21 is between the smoother bottom roll 12b forms a first nip N _1, the wet web 1 is directed to the first nip N _1, the first at the exit of the nip portion N _1, the difference in surface smoothness between the felt 6a and smoother bottom roll 12b, is separated from the felt 6a, is transferred to the smoother lower roller 12b. In the nip portion N1, air is sucked by the suction transfer roll 21, so that blowing does not occur.
On the downstream side, the smoother bottom roll 12b forms a _second nip portion N2 with the smoother top roll 12a.

The smoother top roll 12a and the smoother bottom roll 12b are provided with a hard cover (eg, hard rubber) as a hard material on the surface in order to increase the surface smoothness, and the hard cover has a hardness of 99 ° or more according to JIS standards. It is desirable to have
Wet web 1 granted the surface pressure at the first nip N ₁ is carried on the felt 6a, since the surface smoothness of the Smoother lower roller 12b is higher than the felt 6a, felt in the first nip N ₁ It is separated from 6a and transferred to the surface of the smoother bottom roll 12b. Wet web 1 is transferred to the surface of the Smoother lower roller 12b is transported to the second nip N _2.

The paper passing belt 13 passed along with the wet paper web 1 at the second nip portion N ₂ is made of an elastic member (for example, rubber), has a smooth surface and has a slight air permeability (that is, can absorb some water), and guides it. Nipped at the second nip portion N ₂ together with the wet paper 1 through the roll 18.
Paper feeding belt 13, to improve the paper feeding of the wet web 1 by passing through the nip N ₂ with the wet web 1, also undergo elastic deformation at the nip portion, so that can be secured nip width.

The paper feeding belt 13, to have a lower surface smoothness than the surface smoothness of the smoother bottom roll 12b, so as to transfer to the surface of Smoother lower roller 12b the wet paper 1 at the exit of the nip portion N ₂ ing. Further, with the fine breathable paper feeding belt 13, blowing the aforementioned it is prevented from occurring in the second just before the nip N _2.

The wet paper 1 is applied with a nip pressure at the nip portion N ₂ of the smoother top roll 12 a and the smoother bottom roll 12 b together with the paper passing belt 13, and smoothing processing is performed on both sides of the wet paper 1. Thereafter, since the smoother bottom roll 12b has a higher surface smoothness than the paper passing belt 13, the wet paper 1 is continuously conveyed while adhering to the surface of the smoother bottom roll 12b.

The paper passing belt 13 is not necessarily required if the above-described blowing is not required, and may be passed through the _second nip portion N2 only with the wet paper 1; however, in this case, a soft cover (for example, a rubber cover) ) Is wound around the rubber roll to reduce the surface smoothness of the smoother top roll 12a below the surface smoothness of the smoother bottom roll 12b, thereby maintaining adhesion of the wet paper to the smoother bottom roll 12b. At the same time, the surface of the smoother top roll 12a is made soft so that the nip width is secured.

When the paper passing belt 13 is present, when blowing occurs at the nip portion N2, the guide roll 18 is lowered, and the paper passing belt 13 is pressed (wrapped) against the smoother bottom roll 12b, thereby suppressing the blowing. .
The use of a slightly air-permeable paper passing belt is preferable in that blowing can be prevented immediately before the second nip portion N2. On the other hand, by lowering the guide roll 18 and pressing and wrapping the paper passing belt 13 against the smoother bottom roll 12b, the blowing can be suppressed. Therefore, if importance is attached to the point of improving the surface smoothness of the wet paper, A breathable belt can also be used.
Thereafter, the wet paper 1 is transferred to the dryer part 3 together with the canvas 7c, and the wet paper 1 is dried through the first dryer roll 3a, the second dryer roll (not shown), and the third dryer roll in this order. Reference numerals 20a and 20b in FIG. 1 are vacuum rolls. In FIG. 1, reference numerals 14 to 19 and 22 denote guide rolls for positioning and forming movement paths of the wet paper 1, the felts 6a and 6b, the paper passing belt 13, and the like.

  According to the first embodiment, like a conventional press part, a transfer roll for supporting the wet paper web 1 from the felt to the paper feed belt by applying surface pressure while the wet paper web 1 is sandwiched between the paper belt and the felt. Therefore, the problem of blowing due to the air pool generated in the nip portion of the transfer roll is solved.

  In addition, since there is no running section of the wet paper carried on the lower surface of the paper passing belt between the transfer roll and the smoothing press roll, the problem of wet paper hanging does not occur. Accordingly, there is no generation of wrinkles due to air accumulation or dripping of wet paper, and stable operation is possible. In addition, the wet paper travel path in the press part can be made shorter and more compact than in the conventional press part.

Further, the surface smoothness of the paper passing belt 13 is only limited to be lower than the surface smoothness of the smoother bottom roll 12b, and it is necessary to attach and remove the wet paper with the same paper passing belt as in the prior art. There is no. Accordingly, since it is easy to set the surface smoothness of the paper passing belt 13, the running of the wet paper does not become unstable depending on the operating conditions of the paper machine.
Accordingly, there is an advantage that the allowable range of values that the surface smoothness of the paper passing belt 13 can take is widened, the degree of freedom of component selection at the time of replacing the paper passing belt is increased, and the life of the parts is increased by relaxing the restrictions.
(Embodiment 2)

Next, an embodiment (Embodiment 2) of the second invention of the present invention will be described with reference to FIG. In FIG. 2, the second embodiment differs from the first embodiment in that the suction transfer roll 21 and the smoother bottom roll 12 b do not directly form the first nip portion N ₁ , but the suction transfer roll 21. the nip roll 12c composed of a crown variable roll provided on the downstream side after, and in that to form a first nip portion N ₁ in this nip roll 12c and smoother bottom roll 12b, other configurations are shown in Figure 1 The same parts as those of the first embodiment and the same parts as those of the second embodiment are denoted by the same reference numerals, and the description of the same parts is omitted.

  In Embodiment 2 having such a configuration, the wet paper 1 sandwiched on both sides by the felts 6a and 6b in the press part 2 is pressure-dehydrated by the final press 4 for dehydration, and then is fed to the suction transfer roll 21 via the felt 6a. The other felt 6 b is adsorbed and separated from the wet paper 1.

Then the wet web 1 is the first nip N _1, which is formed by the nip roll 12c and smoother lower roller 12b passes with felt 6a, a first outlet of the nip portion N _1, Sumuzabotomu from the felt 6a Since the surface smoothness of the roll 12b is large, the wet paper 1 is separated from the felt 6a and transferred to the surface of the smoother bottom roll 12b.

Then the wet web 1, by applied surface pressure with paper feeding belt 13 in the second nip N _2, is smoothed. In a second outlet of the nip portion N _2, since more of Smoother lower roller 12b has a higher surface smoothness than the paper feeding belt 13, the wet web 1 sticks to the smoother lower roller 12b are separated from the paper feeding belt 13 It is conveyed as it is and is transferred to the dryer section 3 together with the canvas 7c.

  The nip roll 12c is configured by a crown variable roll, and is configured such that the nip pressure with respect to the smoother bottom roll 12b can be adjusted. The variable crown roll has a configuration in which the surface pressure can be freely adjusted in the circumferential direction and the axial direction of the roll, and the configuration thereof is conventionally known. However, as an example, the configuration disclosed in Japanese Patent Laid-Open No. 61-24813 is disclosed. Is shown in FIG. 3 and FIG.

3 and 4, the crown variable roll 30 supports a cylindrical cell 31 rotatably with a center shaft 32 via a bearing 36, and the center shaft 32 is provided with a pressurizing chamber 35 in the axial direction. The pressure piston 34 is moved by the pressure oil supplied to the pressure chamber 35, the deformation amount of the cell 31 is adjusted by the pressure shoe 33, and the surface pressure between the counterpart roll 37 and the cell 31 can be adjusted. .
The pressure shoe 33, the pressure piston 34, and the pressure chamber 35 can be divided along the roll axis direction so that the surface pressure can be changed along the roll axis direction. Pressure control can be performed.

  According to the second embodiment, the nip pressure with the smoother bottom roll 12b can be freely adjusted by configuring the nip roll 12c with a variable crown roll. When pressure is applied by the suction transfer roll 21 as in the first embodiment, a high surface pressure cannot be applied due to concern about the generation of a suction mark on the paper. The restriction is removed and the nip pressure can be adjusted freely.

If the nip roll 12c is provided above the suction transfer roll 21, in the wet paper running section between the nip roll 12c and the suction transfer roll 21, the wet paper running path is arranged in the vertical direction. There is no risk of gravity in the direction of peeling. Further, the wet paper web path of the press part can be made short and compact in the horizontal direction.
In the first and second embodiments, the dehydrating press is only the final dehydrating press 4. However, literally, a plurality of dehydrating presses may be separately provided before the final dehydrating press.

  According to the present invention, in the final step of the press part of the paper machine, when the wet paper subjected to the pressure dehydration process in the press part is transferred to the smoothing press roll, the transfer roll is not required and is generated in the nip portion of the transfer roll. This eliminates the accumulation of air and the dripping of the wet paper between the transfer roll and the smoothing press roll, thereby preventing the generation of wrinkles and enabling stable running of the wet paper in the press part. .

It is a block diagram of embodiment (Embodiment 1) of the 1st invention of this invention. It is a block diagram of embodiment (Embodiment 2) of the 1st invention of this invention. It is a vertical sectional elevation view showing an example of a crown variable roll used in the second embodiment. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3. It is a block diagram of the press part of the conventional paper machine. (A) And (b) is the partially expanded view and partially expanded perspective view of the press part of the conventional paper machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wet paper 2 Press part 4 Final press for dehydration 4a Shoe module 4b Press bottom roll 5a Suction pick-up roll 5b Suction roll 6a, 6b Felt 8 Wire 12 Smoothing press 12a Smoother top roll (2nd smoothing roll)
12b Smoother bottom roll (first smoothing roll)
12c Nip roll 13 Passing belt 21 Suction transfer roll a Traveling direction of wet paper 1 k Air pool m Drooping down N ₁ First nip portion N ₂ Second nip portion

Claims (6)

In the wet paper smoothing method by the smoothing press, which is used as the final stage press of the paper machine press process and functions to smooth the surface of the running wet paper,
Separating the wet paper from the final press of the dewatering press of the paper machine with both sides being supported by the felt by adsorbing the wet transfer paper to the suction transfer roll through the one felt; and
By passing the wet paper carried on the one felt through the first nip formed by the suction transfer roll and the first smoothing roll on the downstream side of the step, Transferring from a felt to the first smoothing roll;
A method of smoothing wet paper, comprising the step of smoothing the wet paper through a second nip formed by the first smoothing roll and the second smoothing roll. In the wet paper smoothing method by the smoothing press, which is used as the final stage press of the paper machine press process and functions to smooth the surface of the running wet paper,
Separating the wet paper from the final press of the dewatering press of the paper machine in a state where both sides are supported by the felt by adsorbing the wet transfer paper to the suction transfer roll through the one felt; and
By passing the wet paper carried on the one felt through a first nip formed by a nip roll and a first smoothing roll provided on the downstream side of the step, the wet paper Transferring from a felt to the first smoothing roll;
A method of smoothing wet paper, comprising the step of smoothing the wet paper through a second nip formed by the first smoothing roll and the second smoothing roll. A performs a smoothing process through paper feeding belt together with the wet paper web to the second nip portion, the sheet passing belt has elasticity, and surface smoothness of the surface in contact with the wet paper in the paper feeding belt The wet paper smoothing method according to claim 1, wherein the surface smoothness of the first smoothing roll is lower than that of the first smoothing roll. In the press part of the paper machine provided with the smoothing press that is provided as the final stage press of the paper machine press process and functions to smooth the surface of the running wet paper,
A suction transfer roll that separates the other felt from the wet paper by adsorbing the wet paper from the final press of the dewatering press of the paper machine while the both sides are supported by the felt through the one felt;
A first smoothing roll that forms a first nip portion with the suction transfer roll on the downstream side of the adsorption step to transfer the wet paper from the one felt;
A second smoothing process is performed by forming a second nip part with the first smoothing roll on the downstream side of the first nip part, and performing a smoothing process through wet paper through the second nip part. A press part of a paper machine, characterized in that the press part is made up of a paper roll. In the press part of the paper machine provided with the smoothing press that is provided as the final stage press of the paper machine press process and functions to smooth the surface of the running wet paper,
A suction transfer roll that separates the other felt from the wet paper by adsorbing the wet paper from the final press of the dewatering press of the paper machine while the both sides are supported by the felt through the one felt;
A first smoothing roll provided on the downstream side of the suction transfer roll;
Forming a first nip portion with the first smoothing roll, and transferring the wet paper adsorbed by the suction transfer roll from the one felt to the first smoothing roll;
A second nip portion is formed between the first nip portion and the first smoothing roll on the downstream side of the first nip portion, and a smoothing process is performed by passing wet paper through the second nip portion. A press part of a paper machine, characterized in that the press part is made up of a paper roll. A smoothing treatment is performed by passing through the second nip portion together with the wet paper, and the surface smoothness of the surface in contact with the wet paper is lower than the surface smoothness of the first smoothing roll and has elasticity. 6. The press part of a paper machine according to claim 4, further comprising a paper belt.

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