JP5199601B2 - Smoothing belt - Google Patents

Description

  The present invention relates to a smoothing belt provided in a smoothing press apparatus suitable for application to a closed draw type paper machine. More specifically, the present invention relates to a smoothing belt provided in a smoothing press apparatus that holds and conveys one surface of a wet paper with a smoothing belt and smoothes the surface of the wet paper.

In general, a paper machine includes a wire part, a press part, and a dryer part. The wire part, the press part, and the dryer part are arranged along the conveyance direction of the wet paper in this arrangement order.
The wet paper is transported while being successively delivered to the paper transporting tools disposed in each of the wire part, press part, and dryer part, and the water is squeezed (ie, squeezed). Finally, it is dried in the dryer part.
The press device arranged in the press part includes a plurality of press mechanisms arranged in series along the conveyance direction of the wet paper web.

Each press mechanism has a pair of endless belt-like papermaking felts and a press. The presses are vertically opposed so as to sandwich a part of each of the pair of papermaking felts. As this press, a pair of rolls (that is, a roll press) is used, or a roll and a shoe (that is, a shoe press) are used.
The wet paper is conveyed by a papermaking felt that travels in the same direction at substantially the same speed. Each press mechanism presses the wet paper and the paper transporting felt with a roll and a roll (or a roll and a shoe) to cause the paper transporting felt to absorb the moisture while squeezing the wet paper. Yes.

  The smoothing press apparatus may be arranged at the final stage of the press apparatus arranged in the press part. This smoothing press apparatus presses the wet paper transported by the smoothing belt together with the smoothing belt to smooth the surface of the wet paper.

  Examples of the paper machine having the press mechanism include a roll press type paper machine and a shoe press type paper machine. In a roll press type paper machine, a press device is provided in a press part that pressurizes a part of a paper transporting felt sandwiching a wet paper while being sandwiched between the rolls. In a shoe press type paper machine, a press device is provided in a press part that pressurizes a part of a paper transporting felt sandwiching a wet paper while being sandwiched between a roll and a shoe.

The paper machine includes an open draw paper machine and a closed draw paper machine. The open draw type paper machine has a section in which wet paper is transported without being held by a transport felt or a transport belt (ie, wet paper alone).
The closed draw type paper machine transports the wet paper in a state where both sides or one side of the wet paper is always held by a transport felt or a transport belt. In this closed draw type paper machine, wet paper is transported while being held by a transport felt or a transport belt, so paper can be made at high speed. However, on the other hand, in the closed draw type paper machine, at least one surface of the wet paper is in contact with the transport felt or the transport belt. As a result, in the wet paper, there is a possibility that the smoothness of the surface in contact with the transport felt or the transport belt may be lowered.
In particular, shoe presses with high water squeezing and high papermaking efficiency are frequently used in recent closed draw paper machines. For this reason, it has been difficult to improve the smoothness of the wet paper surface in such a paper machine.

Conventionally, in order to improve the smoothness of such wet paper and make it possible to make bulky paper, a smoothing press has been placed at the final stage of the press part, and the wet paper that has been squeezed by this smoothing press It is considered to smooth the surface.
However, most of the conventional smoothing presses are arranged in an open draw type paper machine, and it has been difficult to improve the smoothness of the wet paper surface while making paper at high speed.

  Further, as a conventional paper machine in which a smoothing press is provided in a closed draw type paper machine, it has been proposed in Patent Document 1 (International Publication WO 2004/101885). In this paper machine, one surface of the wet paper is held by an elastic member, and the wet paper is pressed together with the elastic member by a pair of press rolls to smooth the wet paper surface.

International Publication No. WO 2004/101885

The smoothing press of the paper machine disclosed in Patent Document 1 uses an elastic member that is pressed together with the wet paper by a pair of press rolls while holding one surface of the wet paper.
This elastic member is a paper passing belt that does not have air permeability or a surface property improving felt that has air permeability. A rubber belt or the like is exemplified as the paper passing belt having no air permeability. Further, as the felt for improving surface properties, a felt having a slight air permeability with an air permeability of 10 cm ³ / (Sec · cm ² ) or less is exemplified.
However, in recent years, there has been an increasing demand for papermaking at higher speed and further smoothing of the wet paper surface. In order to satisfy these requirements, conventional paper machines are not always sufficient, and there is room for improvement.

  The present invention has been made in view of the above-described problems, and is provided in a smoothing press apparatus suitable for application to a closed draw type paper machine that smoothens the wet paper surface and enables high speed papermaking. An object of the present invention is to provide a smoothing belt that can be used.

  In order to achieve the above-described object, a smoothing press device and a smoothing belt according to the present invention are characterized by having any one of configurations 1 to 6 described below.

(Configuration 1): A smoothing press apparatus includes a first press roll having a smooth surface, a second press roll having a smooth surface and disposed opposite to the first press roll, the first press roll, A closed draw type papermaking comprising: a smoothing belt that is pressed together with wet paper by the second press roll to smooth the surface of the wet paper; and a papermaking felt that conveys the wet paper and passes it to the smoothing belt. A smoothing press device disposed in a press part of the machine, wherein the smoothing belt is formed on a substrate, a first butt layer formed on a wet paper side surface of the substrate, and a roll side surface of the substrate. A second batt layer; and a porous thin film layer formed on a wet paper side surface of the first batt layer so as to be in direct contact with the wet paper.
(Configuration 2): In the smoothing press apparatus described in (Configuration 1), the porous thin film layer of the smoothing belt is a foamed resin layer. The foamed resin layer is formed by mixing a polyurethane resin, a plurality of types of surfactants having different hydrophilicities, and an inorganic compound powder in a solvent to form a mixture, and the wet paper web side surface of the first batt layer The mixture is impregnated to form an impregnated layer, and the impregnated layer is brought into contact with water.
(Configuration 3): In a smoothing press apparatus according to the (structure 2), the foamed resin layer ^is a deposition amount ranging from 50 g / m 2 to 150 g / ^{m 2,} air permeability of the smoothing belt is 1cm in the range of ^{3 / cm 2 / sec~5cm 3 /} cm 2 / sec.
(Structure 4): In the smoothing press apparatus according to (Structure 2) or (Structure 3), the wet paper web surface of the foamed resin layer is polished so that air bubbles are opened and the surface is smooth. Yes.
(Configuration 5): In the smoothing press apparatus according to (Configuration 2), the surfactant is an anionic surfactant such as a carboxylate, sulfate, sulfonate, phosphate, and polyethylene. A plurality of different surfactants selected from nonionic surfactants such as glycol type, polyhydric alcohol type, etc., and having a degree of hydrophilicity different by at least 1 or more due to HLB (hydrophilic hydrophobic balance) Has an HLB value.
(Configuration 6): In the smoothing press apparatus described in (Configuration 2), the powder of the inorganic compound is a mixture of one or more selected from sodium bicarbonate, sodium carbonate, sodium chloride, and sodium nitrate. .

According to the smoothing press apparatus of the above (Configuration 1), the wet paper is conveyed by the permeable papermaking felt. Then, the wet paper is transferred to a smoothing belt having a foamed resin layer on the wet paper side surface of the first batt layer. Further, the surface of the wet paper can be smoothed by pressing the smoothing belt and the wet paper with a pair of press rolls.
The wet paper is sandwiched between a papermaking felt and a smoothing belt, and nip pressure is applied to the wet paper. Then, the wet paper web transported generally has a property of sticking to a smooth surface or a harder surface. Therefore, the wet paper transported by the paper transporting felt has high hardness and is reliably delivered to the smoothing belt having a smooth surface. Further, since the wet paper is pressed by a pair of press rolls together with the smoothing belt and comes into contact with the smooth surface of the smoothing belt, the wet paper surface is smoothed.
The smoothing belt includes a foamed resin layer on the wet paper web side surface of the first bat layer. Therefore, a bulky smooth wet paper surface can be obtained even with high-speed papermaking due to the impact relaxation property (cushioning property) by the first bat layer and the denseness of the foamed resin layer.

According to the smoothing press apparatus according to the above (Configuration 2) to (Configuration 6), the openings of the foamed resin layer can be made into uniform, dense and fine continuous pores. Therefore, in the foamed resin layer, the effect of sucking wet paper through the pores and the surface smoothness function effectively.
As a result, the wet paper can be reliably received from the paper transporting felt, so that the wet paper having high bulk and good surface smoothness can be obtained. At the same time, it is possible to obtain a foamed resin layer having good durability even at high speed papermaking.

Further, the smoothing press apparatus has the following (Configuration 7) or (Configuration 8).
(Structure 7): In the smoothing press apparatus according to (Structure 1), the porous thin film layer of the smoothing belt has a funnel-shaped opening that gradually spreads in the wet paper side surface direction, and It is an apertured resin layer having an aperture ratio of 3% to 30% on the wet paper side surface.
(Structure 8): In the smoothing press apparatus described in (Structure 1), the porous thin film layer of the smoothing belt has a reverse funnel-shaped aperture that gradually spreads inward from the wet paper side surface. In addition, it is an apertured resin layer having an aperture ratio of 1% to 10% on the wet paper side surface.
According to the smoothing press device of the above (Configuration 7) to (Configuration 8), the wet paper transported by the paper transporting felt is reliably delivered to the smoothing belt having high hardness and smooth surface. Further, the wet paper is pressed by a pair of press rolls together with the smoothing belt and comes into contact with the smooth surface of the smoothing belt, so that the wet paper surface is smoothed.
The smoothing belt includes an aperture resin layer on the wet paper web side surface of the first bat layer. Therefore, according to the smoothing belt of the present invention, a wet paper having a bulky and smooth surface can be obtained even with high speed papermaking due to the cushioning property by the first batt layer and the denseness of the aperture resin layer.

The smoothing belt according to the present invention is provided in a smoothing press device and is pressed together with wet paper by a pair of press rolls to smooth the surface of the wet paper. The smoothing belt is in direct contact with the base, the first butt layer formed on the wet paper side surface of the base, the second butt layer formed on the roll side surface of the base, and the wet paper. A porous thin film layer formed on the wet paper web side surface of the first batt layer.
In the smoothing belt, the porous thin film layer is formed by mixing a polyurethane resin, a plurality of types of surfactants having different hydrophilicities, and an inorganic compound powder in a solvent to form a mixture. of the form from the wet paper web side surface impregnated layer impregnated with said mixture, Ru foamed resin layer der formed by contacting the impregnated layer with water.
In the smoothing belt, the foamed resin layer ^is a deposition amount ranging from ^{50g / m 2 ~150g / m 2} , air permeability of the smoothing belt is ^{1cm 3 / cm 2 / sec~5cm 3} / cm 2 / A range of sec is preferred.
It is preferable that the wet paper web side surface of the foamed resin layer of the smoothing belt is polished so that bubbles are opened and the surface is smooth. The surfactant is an anionic surfactant such as a carboxylate, sulfate ester, sulfonate or phosphate ester salt, and a nonionic surfactant such as a polyethylene glycol type or a polyhydric alcohol type. A plurality of different surfactants selected from the above, preferably having different HLB values of at least one or more hydrophilicity by HLB (Hydrophilic Hydrophobic Balance).
In the smoothing belt, the inorganic compound powder is a mixture of one or more selected from sodium bicarbonate, sodium carbonate, sodium chloride and sodium nitrate.
The porous thin film layer of the smoothing belt has a funnel-shaped opening gradually spreading in the wet paper side surface direction, and the open area ratio of the wet paper side surface is in the range of 3% to 30%. It is preferably an open resin layer.
The porous thin film layer of the smoothing belt has a reverse funnel-shaped opening gradually spreading inward from the wet paper side surface, and the wet paper side surface has a hole area ratio of 1% to 10%. An apertured resin layer in the range may be used.

As described above, in the present invention, wet paper is conveyed by the papermaking felt and delivered to the smoothing belt. The wet paper is pressed with a pair of press rolls together with the smoothing belt to smooth the wet paper surface.
Accordingly, the wet paper can be reliably transferred from the paper transporting felt to the smoothing belt, and the smoothing belt includes the foamed resin layer on the wet paper side surface of the first butt layer. Due to the impact relaxation property (cushioning property) of the layer and the denseness of the foamed resin layer, a bulky smooth wet paper surface can be obtained even at high speed papermaking.

The present invention has been briefly described above.
The details of the present invention will be further clarified by reading through the best mode for carrying out the invention described below with reference to the accompanying drawings.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic configuration diagram of a closed draw type paper machine equipped with a smoothing press apparatus and a smoothing belt according to a first embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a paper transporting felt, and FIG. 3 is the paper machine It is a longitudinal cross-sectional view of the smoothing belt arrange | positioned in.

As shown in FIG. 1, in a closed draw type paper machine, a press part 11 and a dryer part 13 are arranged in series in the conveying direction of the wet paper W in that order. A smoothing press apparatus 100 is disposed in the press part 11.
The smoothing press 17 constitutes the smoothing press apparatus 100. The smoothing press 17 is arranged as a final stage press of the press part 11 on the downstream side of the final squeezing press rolls 15A and 15B of the press part 11.
The squeezing press rolls 15 </ b> A and 15 </ b> B are disposed to face each other across the conveyance path of the wet paper W. The transport felt 19 and the paper transport felt 21 sandwich and transport the wet paper W. The squeezing press rolls 15A and 15B squeeze the wet paper W by sandwiching and pressing the transport felt 19 and the paper transport felt 21 together with the wet paper W.

The smoothing press 17 is for smoothing the surface of the wet paper web W that has been squeezed and transporting the wet paper web W to the dryer part 13. The smoothing press 17 includes a first press roll 23 and a second press roll 25 that are arranged to face each other with the conveyance path of the wet paper W interposed therebetween. Both the first press roll 23 and the second press roll 25 have a high surface hardness and a smooth surface.
The paper transporting felt 21 transports the wet paper W and delivers it to the smoothing belt 27. The smoothing belt 27 travels while holding one surface of the wet paper web W. The first press roll 23 and the second press roll 25 smooth the surface (both sides) of the wet paper W by pressing the smoothing belt 27 together with the wet paper W.

  Between the squeezing press rolls 15A and 15B and the smoothing press 17, a pair of transfer rolls 29A and 29B are arranged. The transfer rolls 29 </ b> A and 29 </ b> B press the wet paper W transported by the paper transporting felt 21 between the paper transporting felt 21 and the smoothing belt 27 to generate nip pressure, and the wet paper W is applied to the smoothing belt 27. It is designed to be transported.

  As shown in FIG. 2, in the paper transporting felt 21, bat layers 43 made of staple fibers 47 are entangled and integrated on both surfaces of the base body 41 by needle punching. In other words, the paper transporting felt 21 is a permeable felt provided with a first butt layer 43A formed on the wet paper side surface and a second butt layer 43B formed on the roll side surface.

Next, the smoothing belt 27 used in the smoothing press apparatus 100 of this embodiment will be described in detail.
As shown in FIG. 3, in the smoothing belt 27, bat layers 43 made of staple fibers 47 are entangled and integrated on both surfaces of the base body 41 by needle punching. That is, the smoothing belt 27 includes a base body 41, a first butt layer 43 </ b> A formed on the wet paper side surface of the base body 41, and a second butt layer 43 </ b> B formed on the roll side surface of the base body 41. . The porous thin film layer 45 is formed on the wet paper web side surface of the first batt layer 43A so as to be in direct contact with the wet paper web W.
As the base 41, for example, a thread material in the MD (Machine Direction) direction (in other words, the running (flowing) direction of the wet paper web W) and a thread in the CMD (Cross Machine Direction) direction (in other words, the width direction). A woven fabric woven with materials is used.
In addition, as the base body 41, a material in which both yarn materials are overlapped without being woven, a film or a knitted fabric, a material in which a narrow band is wound in a spiral may be used. When the base 41 is a film or a knitted fabric, for example, polyamide, polyester, aromatic polyamide, aromatic polyimide, high molecular weight polyethylene or the like is used as the base 41.

In the present invention, a suitable method for forming the porous thin film layer 45 is employed. In this method, a polyurethane resin, a plurality of types of surfactants having different degrees of hydrophilicity (HLB: hydrophilic and hydrophobic balance), and an inorganic compound powder are mixed in a solvent to form a mixture. The impregnated layer is formed by impregnating the mixture from the wet paper web side surface of the layer 43A, and the foamed resin layer is formed by bringing the impregnated layer into contact with water.
That is, the mixture is impregnated from the wet paper web side surface of the first batt layer 43A to form an impregnated layer, and the mixture is infiltrated into the first batt layer 43A. Then, by laminating the mixture on the first batt layer 43A and then bringing it into contact with water, the solvent and the inorganic compound powder can be extracted and converted from the impregnated layer to the porous foamed resin layer. it can.
This method is generally called a wet film forming method. By this method, the foamed resin layer can be formed inside and on the first butt layer 43A.

  As the resin for forming the foamed resin layer that is the porous thin film layer 45 of the present invention, a resin that forms a foam (foam) such as polyurethane resin, polyvinyl chloride resin, polyvinyl alcohol resin, or acrylic resin is preferably used. . In particular, polyurethanes such as polyester-based polyurethane, polyether-based polyurethane, and polycarbonate-based polyurethane having high mechanical strength can be suitably used.

As the resin forming the foamed resin layer of the present invention, an aqueous resin or emulsion resin having a solid content of 20 wt% to 50 wt% and a viscosity at 25 ° C. of 10,000 cp to 200,000 cp should be used. Is preferred.
By polishing the wet paper web side surface of the foamed resin layer of the present invention, it is possible to open bubbles that have been blocked up to that time, and at the same time, the smoothness of the surface of the smoothing belt 27 is improved.

In the present invention, surfactants for forming the mixture include anionic surfactants such as carboxylate, sulfate ester salt, sulfonate salt and phosphate ester salt, and polyethylene glycol type, polyhydric alcohol type and the like. A plurality of different surfactants selected from nonionic surfactants are used.
The plurality of types of surfactants have different HLB values having a hydrophilicity degree of at least 1 or more due to HLB (hydrophilic hydrophobic balance).
A hydrophilic surfactant having a high HLB value has a property of promoting film formation by a wet film forming method. On the contrary, a hydrophobic surfactant having a low HLB value has a property of suppressing film formation by a wet film forming method.
As a result, a pore size within a certain range can be obtained by using a hydrophilic surfactant having a high HLB value and a hydrophobic surfactant having a low HLB value together. That is, by using a plurality of types of surfactants, the opening of the foamed resin layer can be defined in the range of 20 μm to 100 μm in terms of the hole diameter.

  The amount of the surfactant used in the present invention is preferably 1% by weight to 5% by weight with respect to the resin amount of the foamed resin layer. The reason is that if the amount of the surfactant used is less than 1% by weight with respect to the resin amount of the foamed resin layer, the ability to form the foamed resin layer is inferior. Further, if the amount of the surfactant used is more than 5% by weight with respect to the resin amount of the foamed resin layer, the mixture will be excessively foamed, and the impregnation of the first batt layer 43A on the wet paper side surface will deteriorate. It is.

  The inorganic compound powder used in the present invention is preferably a mixture of one or more selected from sodium bicarbonate, sodium carbonate, sodium chloride and sodium nitrate. This mixture dissolves easily in water, hardly dissolves in the solvent, and forms good pores by a wet film-forming method. Therefore, sodium hydrogen carbonate is particularly preferable as the inorganic compound powder.

In the wet film forming method of the present invention, the mixture is impregnated from the wet paper web side surface of the first batt layer 43A to form an impregnated layer and a laminate thereon. Thereafter, the impregnated layer and the laminated layer thereon are brought into contact with water, and the inorganic compound powder is extracted together with the solvent to be opened.
Since the site composed of the impregnated layer and the laminated layer thereon has good contact with water, fine and continuous pores can be obtained. Note that the impregnation layer inside the first batt layer 43 </ b> A is delayed in contact with water and may leave a part of the powder of the inorganic compound, but does not hinder the function of the smoothing belt 27.

The solvent used in the present invention is preferably one that can uniformly disperse a foamed resin layer, a plurality of types of surfactants having different HLBs, and an inorganic compound powder, and can maintain a stable dispersion of the mixture.
In the present invention, as the solvent, dimethylformamide (DMF), which has good dispersion stability of the mixture, is excellent in extractability with water (that is, miscibility with water, solubility in water) and is easy to handle, can be suitably used. .

When the adhesion amount of the foamed resin layer is less than 50 g / m ² , the air permeability of the smoothing belt 27 is high and the hardness is low, and the smoothness of the surface of the smoothing belt 27 on the wet paper side is lowered. As a result, it becomes difficult to receive the wet paper W from the paper transporting felt, and the wet paper W with good surface smoothness cannot be obtained.
On the contrary, if the amount of the foamed resin layer attached is more than 150 g / m ² , the impact relaxation property (cushioning property) of the first butt layer 43A of the smoothing belt 27 is deteriorated, so that the paper is bulky at high speed. The wet paper surface cannot be obtained.
Therefore, the foamed resin layer of the present invention ^is the adhesion amount in the range of ^{50g / m 2 ~150g / m 2} . Further, air permeability of the smoothing belt 27 ^is in the range of ^{1cm 3 / cm 2 / sec~5cm 3} / cm 2 / sec.

An example is shown about the procedure for forming the foamed resin layer of 1st Embodiment of this invention. However, the present invention is not limited to this procedure.
In the formation of the foamed resin layer, which is the porous thin film layer of the present invention, 100 parts of an aqueous polyurethane resin (active ingredient concentration: 30%), 120 parts of DMF as a solvent, nonionic surfactant (polyoxyethylene) Lauryl ether) Emulgen 105 (Kao Corporation: HLB 9.7) and Emulgen 106 (Kao Corporation: HLB 10.5) were mixed in this order, 80 parts of sodium bicarbonate powder while stirring. To form a mixture.
Next, as shown in FIG. 3, the mixture is impregnated from the surface of the first batt layer 43A and penetrates into the first batt layer 43A. Furthermore, after laminating the mixture on the first batt layer 43A, the mixture is passed through a coagulation tank filled with water to convert the impregnated layer into a foamed resin layer. What is necessary is just to determine suitably the magnitude | size of a coagulation tank, the contact time with water, etc. by the thickness of an impregnation layer.
Further, after the foamed resin layer is dried, the wet paper side surface of the foamed resin layer is polished with abrasive paper, a grid brush, or the like. Thereby, the denseness and smoothness of the wet paper side surface of the foamed resin layer can be adjusted.

FIG. 5 shows the surface of the foamed resin layer of the smoothing belt 27 of the first embodiment. FIG. 6 shows a cross section of the smoothing belt 27 including the foamed resin layer of the first embodiment.
The pore diameter of the foamed resin layer is 50 μm to 100 μm, the adhesion amount of the foamed resin layer is 100 g / m ² , the thickness is 500 μm, and the air permeability is 2.3 cm ³ / cm ² / sec.

(Second Embodiment)
Next, the smoothing press apparatus 200 and the smoothing belt 127 according to the second embodiment of the present invention will be described with reference to FIGS. 3, 4, and 7 to 9.
FIG. 4 is a schematic configuration diagram of a closed draw type paper machine equipped with the smoothing press device 200 of the second embodiment. FIG. 7 is a surface view of the aperture resin layer (porous thin film layer 45) of the second embodiment, FIG. 8 is an enlarged view of the aperture portion, and FIG. 9 is a smoothing including the aperture resin layer of the second embodiment. 4 is an enlarged view of a cross section of a belt 127. FIG.

As shown in FIG. 4, the smoothing press apparatus 200 of the second embodiment is configured in the same manner as the smoothing press apparatus 100 of the first embodiment. A suction roller 123 is provided instead of the pair of transfer rolls 29A and 29B. The same papermaking felt 21 as that of the first embodiment can be used as the papermaking felt 121.
The configuration of the smoothing belt 127 is different from the smoothing belt 27 of the first embodiment. Since other parts are the same as those of the smoothing press apparatus 100 of the first embodiment, the same parts are denoted by the same or corresponding reference numerals, and the description thereof will be simplified or omitted.

As shown in FIG. 3, in the smoothing belt 127 of the second embodiment, bat layers 43 made of staple fibers 47 are entangled and integrated on both surfaces of the base body 41 by a needle punch.
That is, the smoothing belt 127 includes a first butt layer 43A formed on the wet paper side surface and a second butt layer 43B formed on the roll side surface. A porous thin film layer 45 is disposed on the wet paper web side surface of the first batt layer 43A so as to be in direct contact with the wet paper web W. The porous thin film layer 45 is an open resin layer.

Next, the operation of the closed draw paper machine according to the second embodiment will be described.
As shown in FIG. 4, the wet paper W is sucked by the suction roll 61 and one surface of the wet paper W is held by the transport felt 19. The wet paper W is squeezed by the squeezing press rolls 15 </ b> A and 15 </ b> B, and then sucked by the suction roll 63 and conveyed by the papermaking felt 121.
The wet paper W is further sucked by the suction roll 123 and transferred from the papermaking felt 121 to the smoothing belt 127. The papermaking felt 121 is a permeable felt having the same configuration as the papermaking felt 21 of the first embodiment, and the surface thereof is a relatively rough surface.

On the other hand, an apertured resin layer that is a porous thin film layer 45 is disposed on the wet paper web side surface of the smoothing belt 127. Therefore, the surface of the smoothing belt 127 is extremely smooth.
The wet paper W has a property of sticking to a smoother surface when nipped. Further, suction by the suction roll 123 acts on the wet paper web W through the aperture resin layer of the smoothing belt 127. Therefore, the wet paper W is reliably transferred by the smoothing belt 127.
Then, the wet paper W is supplied to the smoothing press 17 in a state where one surface thereof is held by the smoothing belt 127. Since the wet paper W is pressed by the first press roll 23 and the second press roll 25 together with the smoothing belt 127, both surfaces of the wet paper W are smoothed.

At this time, one surface of the wet paper web W comes into contact with the surface of the open resin layer (porous thin film layer 45) of the smoothing belt 127, which is a very smooth surface. Since the other surface of the wet paper W is in contact with the second press roll 25 having a high surface hardness and a smooth surface, the wet paper W is obtained with a very fine surface roughness.
The wet paper W is further conveyed to the dryer part 13 via the canvas 65 and dried by the dryer 67.

The opening resin layer (porous thin film layer 45) of the smoothing belt 127 of the second embodiment is formed by applying opening means such as a laser (for example, carbon dioxide laser) or an ultra-high pressure water flow to the resin sheet. Holes can be opened from one surface side of the sheet. In the ultra-high pressure water flow, for example, the nozzle diameter is 0.2 mm and a water flow with a pressure of 9.8 × 10 ⁷ Pa to 2.9 × 10 ⁸ Pa (1,000 to 3000 kgf / cm ² ) is applied to open the water flow. Can be perforated.
Openings in the resin sheet can be formed by being randomly arranged (or in a grid or staggered pattern with a pitch interval of 0.5 mm to 5 mm).

The aperture ratio of the aperture resin layer of the smoothing belt 127 is appropriately adjusted by the aperture diameter and the pitch interval of the apertures. In addition, the aperture ratio of the apertured resin layer of the present invention is the ratio of the aperture area that occupies the wet paper web surface on the side where the aperture resin layer directly contacts the wet web W.
The porous thin film layer 45 of the smoothing belt 127 shown in FIGS. 8 and 9 has a funnel-shaped opening that gradually spreads in the direction of the surface of the wet paper web. In the case of this aperture portion, the aperture resin layer preferably has an aperture ratio of 3% to 30% on the wet paper side surface.

In addition, the porous thin film layer of the smoothing belt according to the modification of the second embodiment has a reverse funnel-shaped opening that gradually spreads inward from the wet paper side surface. In the case of this aperture portion, the aperture ratio on the wet paper web surface is preferably an aperture resin layer in the range of 1% to 10%.
One reason for this is that the aperture ratio of the apertured resin layer is in the above range (in the range of 3% to 30% when the aperture is funnel-shaped, or from 1% to when the aperture is reverse funnel-shaped. This is because the transfer state of the wet paper W from the paper transporting felt 121 is deteriorated when it is less than 10%. Another reason is that the aperture ratio of the apertured resin layer is within the above range (in the range of 3% to 30% when the aperture is funnel-shaped, or 1% when the aperture is reverse funnel-shaped. This is because the opening portion is transferred so as to mark the surface of the wet paper W or the wet paper smoothness is deteriorated.

Since the aperture resin layer is uniform and dense, the wet paper web W can be reliably received from the paper transporting felt. When the aperture resin layer has a funnel-shaped aperture that gradually spreads in the direction of the surface of the wet paper web, the mark on the aperture may be transferred to the surface of the wet paper web W.
However, since the apertured resin layer can remarkably exhibit the effect of sucking the wet paper W through the suction roll 123, there is an advantage that the wet paper W can be reliably received from the paper transporting felt 121.

In any of the aperture resin layers (porous thin film layer 45) of the smoothing belt 127 shown in FIGS. 3 and 7 to 9, the aperture portion has a funnel shape that gradually spreads in the direction of the wet paper web surface. . In this case, the aperture diameter of the aperture resin layer is 500 μm at the upper part of the funnel-shaped part and 200 μm at the lower part of the funnel-shaped part.
The opening pattern of the opening resin layer of the smoothing belt 127 shown in FIG. 7 has a grid shape, and the plurality of opening portions are arranged at a pitch interval of 2 mm. This open resin layer has an air permeability of 10 cm ³ / cm ² / sec and an open area ratio of 3%.

In the smoothing belt according to the modification of the second embodiment, the aperture resin layer has a reverse funnel shape and a smooth surface, so that the mark of the aperture portion is not transferred to the surface of the wet paper web. . Therefore, the wet paper web W which is bulky and has good surface smoothness can be obtained.
The aperture resin layer also has the effect of sucking the wet paper W through the suction roll 123, so that the wet paper W can be reliably received from the paper transporting felt 121, especially in high speed paper making. The durability of W is good.

  As the resin sheet, a resin sheet made of polyurethane, polyamide, polyester, aromatic polyamide, aromatic polyimide, high molecular weight polyethylene, or the like can be used. The resin sheet has a thickness of 0.1 mm to 5 mm.

In the smoothing belt 127 of the second embodiment, the bat layer 43 is entangled and integrated with the wet paper web side surface and the roll side surface of the base body 41 by a needle punch. Thereafter, the resin sheet is laminated.
For example, in the smoothing belt 127, the resin sheet is thermally activated, and the resin sheet is bonded to the surface of the first butt layer 43A integrated with the wet paper web side surface of the base 41. Thereafter, the resin sheet can be opened by an opening means.
A resin sheet that has been previously opened may be bonded (laminated) to the surface of the first butt layer 43A. In this way, it is possible to obtain a perforated resin layer (porous thin film layer 45) having a funnel-shaped perforated portion that gradually spreads in the wet paper side surface direction.

On the contrary, the smoothing belt according to the modified example of the second embodiment has a porous resin layer (porous thin film layer) having a reverse funnel-shaped aperture that gradually spreads inward from the wet paper web surface. Is formed.
In order to form this apertured resin layer, a resin sheet that has been previously apertured may be reversed and then bonded to the surface of the first butt layer.

Next, an example of a procedure for forming an aperture resin layer on the smoothing belt 127 according to the second embodiment of the present invention will be described. Note that the present invention is not limited to this procedure.
In order to form the open resin layer as the porous thin film layer 45, the resin sheet is thermally activated by irradiating a polyurethane resin sheet (a thermoplastic polyurethane sheet having a thickness of 0.3 mm) with infrared rays.
Then, as shown in FIG. 3, the resin sheet is placed on the surface of the first butt layer 43 </ b> A and further passed between the pair of rolls. Thereby, the resin sheet is bonded (laminated) to the first butt layer 43A.
Thereafter, the surface of the resin sheet is opened by applying a carbon dioxide laser beam. Then, an opening is formed, and this opening has a funnel shape gradually spreading in the sheet surface direction (FIGS. 8 and 9). Instead of thermally activating the resin sheet, an adhesive may be used, or heat activation and an adhesive may be used in combination.

In addition, an opening part can also be formed in the reverse funnel shape which spread gradually inward from the wet paper web side surface. For this purpose, a carbon dioxide laser beam is applied to the surface of the polyurethane resin sheet in advance to make holes. Then, the opening part has a funnel shape gradually spreading in the sheet surface direction.
Next, the resin sheet is turned upside down and then irradiated with infrared rays to thermally activate the resin sheet. Then, as shown in FIG. 3, the resin sheet is placed on the surface of the first butt layer 43 </ b> A and further passed between the pair of rolls. Thereby, the resin sheet is bonded (laminated) to the first butt layer 43A.
As a result, a smoothing belt having an aperture resin layer in which a reverse funnel-shaped aperture is formed is formed.

If the smoothing belt 127 having the above-described configuration is used, the suction effect by the suction roll 123 acts on the wet paper W via the smoothing belt 127 as compared with the smoothing belt 27 having the foamed resin layer of the first embodiment. .
Therefore, the wet paper W can be reliably transferred from the papermaking felt to the smoothing belt 127. Therefore, the smoothing belt 127 can be preferably used particularly in high-speed papermaking.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.
In the drawings, the same reference numerals denote the same or corresponding parts.

  The smoothing belt provided in the smoothing press apparatus of the present invention can be applied to a closed draw type paper machine that enables paper making at high speed.

It is a schematic block diagram of the closed draw type paper machine provided with the smoothing press apparatus and smoothing belt concerning 1st Embodiment of this invention. It is a longitudinal cross-sectional view of a papermaking felt. It is a longitudinal cross-sectional view of a smoothing belt. It is a schematic block diagram of the closed draw type paper machine provided with the smoothing press apparatus of 2nd Embodiment of this invention. It is a surface view of the foamed resin layer concerning 1st Embodiment of this invention. It is sectional drawing of the smoothing belt concerning 1st Embodiment of this invention. It is a surface view of the apertured resin layer concerning 2nd Embodiment of this invention. It is an enlarged view of the opening part concerning 2nd Embodiment of this invention. It is sectional drawing of the smoothing belt concerning 2nd Embodiment of this invention.

DESCRIPTION OF SYMBOLS 100 Smoothing press apparatus 200 Smoothing press apparatus 11 Press part 13 Dryer part 15A Squeezing press roll 15B Squeezing press roll 17 Smoothing press 19 Conveying felt 21 Papermaking felt 23 1st press roll 25 2nd press roll 27 Smoothing belt 29A Transfer roll 29B transfer roll 41 base 43 butt layer 43A first butt layer 43B second butt layer 45 porous thin film layer 47 staple fiber 121 papermaking felt 127 smoothing belt W wet paper

Claims (7)

A smoothing belt provided in a smoothing press device and pressed with wet paper by a pair of press rolls to smooth the surface of the wet paper,
A substrate;
A first batt layer formed on the wet paper side surface of the substrate;
A second butt layer formed on the roll side surface of the substrate;
A porous thin film layer formed on the wet paper side surface of the first batt layer so as to be in direct contact with the wet paper ;
This porous thin film layer
A polyurethane resin, a plurality of types of surfactants having different hydrophilicity levels, and an inorganic compound powder are mixed in a solvent to form a mixture, and the mixture is impregnated from the wet paper web side surface of the first batt layer. A smoothing belt, which is a foamed resin layer formed by forming an impregnated layer and bringing the impregnated layer into contact with water . The smoothing belt according to claim 1 ,
The foamed resin layer ^is a deposition amount ranging from ^{50g / m 2 ~150g / m 2} , air permeability of the smoothing belt is in the range of ^{1cm 3 / cm 2 / sec~5cm 3} / cm 2 / sec Smoothing belt characterized by that. 3. The smoothing belt according to claim 1 , wherein a wet paper web side surface of the foamed resin layer is polished so that bubbles are opened and the surface is smooth. 4. The smoothing belt according to claim 1 ,
Examples of the surfactant include anionic surfactants such as carboxylates, sulfate esters, sulfonates and phosphate esters, and nonionic surfactants such as polyethylene glycol types and polyhydric alcohol types. A smoothing belt comprising a plurality of selected different surfactants and having different HLB values of at least one or more hydrophilicity by HLB (hydrophilic hydrophobic balance). The smoothing belt according to claim 1 ,
The smoothing belt according to claim 1, wherein the inorganic compound powder is a mixture of one or more selected from sodium hydrogen carbonate, sodium carbonate, sodium chloride and sodium nitrate. The smoothing belt according to claim 1,
The porous thin film layer of the smoothing belt has a funnel-shaped opening portion that gradually spreads in the wet paper side surface direction, and the open area ratio of the wet paper side surface is in the range of 3% to 30%. A smoothing belt, which is an open resin layer. The smoothing belt according to claim 1,
The porous thin film layer of the smoothing belt has a reverse funnel-shaped aperture gradually spreading inward from the wet paper side surface, and the wet paper side surface has a porosity of 1% to 10%. A smoothing belt characterized by being a perforated resin layer in the range.

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