JP3848610B2 - Dryer canvas for papermaking - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a paper making dryer canvas. More specifically, in the drying section of the paper machine, one dryer in which a pair of paper-making dryer canvases, one on each of the upper and lower sides, is wound between a plurality of dryer cylinders and guide rolls and travels. At least a dryer cylinder in which the drive of the dryer cylinder in the cylinder group is driven by a method that is not directly connected to the main drive dryer cylinder by a mechanical connection means such as a gear train and / or is configured to freely rotate. The present invention relates to a paper making dryer canvas that can be suitably used in a drying section that is carried out by a drive system in which there is one or more.
[0002]
[Prior art]
As shown in FIGS. 9 and 10, the paper machine has a drying section in which wet paper is attached to a paper machine dryer canvas (hereinafter abbreviated as “canvas” unless otherwise specified) 1, and a plurality of heating units are provided inside. Generally, a drier cylinder (hereinafter, abbreviated as a cylinder unless otherwise specified) 2 and a guide roll 3 are sequentially run around to dry the wet paper web. Usually, the plurality of cylinders 2 are connected to each group by a gear train, and each group is driven by a main drive unit. The canvas 1 is divided into a group or a group divided into a plurality of groups, as shown in FIG. 9, or as a set of two sheets, one up and down as shown in FIG. , Hanged and used.
[0003]
However, when the cylinders are connected by gear trains for each group, gear shaft bearings, lubrication oil supply to gears, and a machine frame and gear box to support these drive units are necessary and maintained. -It requires labor and cost to manage, and because it has many gear trains, noise is generated during operation.
[0004]
In order to cope with these problems, as shown in FIG. 11, among the plurality of cylinders, the cylinder 2a is driven by the motor, and among the remaining cylinders, the cylinder 2b is the rotational speed of the main drive motor in the group. The other cylinder 2c is connected to the canvas 1 and the wet paper web that is in contact with the canvas 1 by increasing the running tension of the canvas 1 that rotates freely and is not connected to the main drive device. In some cases, a synchronous driving method is used in which the motor is driven by the frictional force.
[0005]
[Problems to be solved by the present invention]
In this case, there is a merit that the noise of the drive part is low and the maintenance work of the apparatus can be reduced, but if the cylinder is freely rotated or a synchronized drive system different from the main drive apparatus is adopted, Compared to the rotational speed of the main drive cylinder 2a, removes dirt and other contaminants such as pitch accumulated on the cylinder surface and water droplets attached to the cylinder surface, especially when the paper width is increased after passing through the paper or in a cylinder with a doctor. When the load on the cylinder changes, such as when the drain amount increases due to poor drainage in the cylinder, if rotational speed unevenness occurs and the speed difference between the cylinders is large, the wet paper is excessive. There is a risk that tension will be applied and that the wet paper will break.
[0006]
In the drying section of the paper machine, as described above, the present invention is configured such that one or two upper and lower canvases are wound between a plurality of cylinders and guide rolls. In at least one cylinder group, the drive of the cylinder is driven by a drive system that is not directly connected by a mechanical connection means such as a main drive cylinder and a gear train, and / or a cylinder that is configured to rotate freely is at least In the drying section that is performed by one or more drive systems, the speed difference between the peripheral speed of the cylinder surface and the peripheral speed of the canvas surface that is in contact with the cylinder surface due to the difference in rotational speed between the cylinders is reduced. Accordingly, an object of the present invention is to provide a canvas that can reduce an excessive load on the wet paper and prevent breakage of the wet paper.
[0007]
[Means for Solving the Problems]
The reason for the high risk of wet paper breakage in the drying section of the drive system is that the canvas runs in a cylinder with a different drive system or runs in a cylinder with a free rotation configuration, It is also considered that excessive tension is applied to the canvas and the canvas itself expands and contracts, so that the wet paper transported to the canvas also excessively expands and contracts.
[0008]
However, a canvas used in a paper machine is usually rotated in contact with a guide roll 3 such as a freely rotating canvas roll as shown in FIG. 10 in addition to the cylinder, and at least the guide roll 3 is provided in the canvas. Although tension for driving is applied, the tensile strength of a general canvas is much larger than the tensile strength of wet paper, and the elongation at the time of normal papermaking including the tension for driving the guide roll 3 is It is very small compared to the breaking elongation of the wet paper, and the wet paper is not directly stretched to the extent that it breaks. In addition, it has a sufficient tensile strength against the tension of rotating one or several free-rotating cylinders.
[0009]
However, in the drying section of the drive system, particularly, wet paper breakage often occurs at the time of paper-making, so the wet paper breakage is not caused by the elongation of the canvas, and is mainly rotated freely with the canvas. It was assumed that slip occurred between the cylinders or between the canvas and the driven motor-driven cylinder, which resulted from excessive stretching of the wet paper.
[0010]
For this purpose, various studies were made on methods for preventing slippage between the cylinder and the canvas. As a result, it was found that the following configuration is effective.
[0011]
That is, the paper machine dryer canvas of the present invention has at least one dryer cylinder group in one dryer cylinder group of a drying section of a paper machine in which a single dryer canvas or a pair of upper and lower dryer canvases travels around. More than one dryer cylinder is driven by a drive system that is not directly connected to the main drive dryer cylinder by mechanical connecting means, and / or is used in a drying section of a paper machine that is configured to freely rotate. The surface of both ears that are in direct contact with the dryer cylinder on the side of the dryer canvas that contacts at least the dryer cylinder In addition, except for the main body surface that does not directly contact the dryer cylinder, the ear is further provided with wear resistance against the contact wear with the palm which is a contact type detection body of the automatic traveling guide of the dryer canvas at the end of the dryer canvas. In the part excluding the reinforcement The inside of the dryer canvas width direction from the both ears, The above A surface property having a larger frictional force than the surface of the main body is added (Claim 1).
[0012]
The present invention also provides: A means for adding a surface property having a large frictional force to the surfaces of both ears that are in direct contact with the dryer cylinder is to apply a synthetic resin. The papermaking dryer canvas according to claim 1, wherein the papermaking dryer canvas is used (claim 2).
[0013]
The present invention also provides: The synthetic resin is polyurethane Claims 2 The papermaking dryer canvas according to claim 3 (Claim 3).
[0014]
The present invention also provides: The synthetic resin is silicone-based Claims 2 The papermaking dryer canvas as described in (4).
[0015]
The present invention also provides: The synthetic resin is applied to a thickness in the range of 0 mm to 0.20 mm. Claims One of 2 to 4 The papermaking dryer canvas according to claim 5 (Claim 5).
[0016]
The present invention also provides: Yarn that is made by twisting a yarn with a high frictional force alone or with a yarn of another material at a part that adds a surface property with a high frictional force to the surfaces of both ears that are in direct contact with the dryer cylinder The yarn is bound to the surface of the dryer canvas, or woven with the fabric constituting yarn of the dryer canvas, or replaced with the fabric constituting yarn of the dryer canvas, and is exposed to the fabric surface of the both ears. Let Claims 1 to 5 A papermaking dryer canvas according to any one of the above (claim 6).
[0017]
The present invention also provides: In one dryer cylinder group of a drying section of a paper machine in which one dryer canvas or a pair of dryer canvases on each of the upper and lower sides circulates, at least one dryer cylinder is a main drive dryer cylinder. A dryer canvas for use in a paper machine driven by a drive system that is not directly connected by a mechanical connecting means and / or a structure that freely rotates, and at least a dryer cylinder of the dryer canvas The surface of both ears that are in direct contact with the dryer cylinder on the surface side that is in contact with the dryer, the inner surface of the dryer canvas in the width direction of the dryer canvas and having a larger frictional force than the surface of the main body that is not in direct contact with the dryer cylinder A single thread made of a material with high frictional force, Alternatively, yarns twisted with yarns of other materials are bound on the surface of the dryer canvas, or woven together with the fabric constituent yarns of the dryer canvas, or the fabric constituent yarns of the dryer canvas Replace and weave and give it to the fabric surface of both ears It is characterized by Ru A paper dryer canvas (Claim 7).
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The canvas of the present invention has a drive system for at least one cylinder in one cylinder group of a drying section of a paper machine in which one canvas or a pair of canvases on each of the upper and lower sides runs around. A canvas used in a drying section of a paper machine that is driven by a drive system that is not directly connected to a main drive cylinder by mechanical connection means and / or is configured to freely rotate, and that contacts at least the cylinder of the canvas The surface of the both ears that are in direct contact with the cylinder on the surface side to which the surface is to be attached is provided with a surface property that has a greater frictional force than the surface of the main body that is in the canvas width direction inner side than the both ears and does not directly contact the cylinder. .
[0019]
As described above, the structure of the drying section of the multi-cylinder dryer for papermaking includes a vertical canvas system in which the cylinders shown in FIG. 10 are arranged in two upper and lower stages, and a type in which cylinders as an improvement plan are arranged in a single row. For example, there is a single-row dryer system as shown in FIG.
[0020]
In the upper and lower canvas system, as shown in FIG. 10, one upper and lower canvas 1 is hung, and usually a plurality of cylinders and guide rolls that are hung as a set of two upper and lower canvases, One group is formed, and usually the cylinders in the group are directly connected by a mechanical connecting means by a gear train and driven by one main drive motor.
[0021]
Similarly, in the single-row dryer system, as shown in FIG. 9, one canvas 1 is hung on a plurality of cylinders and guide rolls, and a portion where one canvas is normally hung is a group. The cylinders in the group are directly connected by a mechanical connecting means by a gear train and driven by one main drive motor.
[0022]
However, as described above, at least one or more cylinders in the group are not directly connected to the main drive cylinder, but each driven motor is attached and driven in synchronization with the main drive cylinder, or the cylinder is freely rotated. It may be driven by the frictional force with the canvas.
[0023]
FIG. 11 shows an upper and lower canvas system, and a group of seven cylinders 2 in total of four upper parts and three lower parts constitutes one group. For example, the upper second cylinder 2a is driven by the main drive motor, and the third The cylinder 2b is driven by a driven motor that detects and rotates in synchronization with the rotation speed of the main motor, and the leading and fourth cylinders 2c are free to rotate and are driven by the frictional force of the canvas 1.
[0024]
Normally, when making a paper, the paper making speed is set to a predetermined speed, and after passing through a tail with a narrow paper width at a stable position, the paper width is gradually widened. The ratio of the width of contact between the canvas and wet paper cylinder with different frictional properties changes as the friction level changes, and the friction force on the cylinder changes. The cylinder is driven by the friction force between the canvas and the wet paper pressed against the canvas. , And even a cylinder that is synchronized with the main drive cylinder may cause a delay in drive synchronization and insufficient rotation speed, resulting in a speed difference between the cylinders and excessive tension on the wet paper web. As described above, the wet paper web may be broken.
[0025]
In the present invention, in the canvas, on the surface of both ears that are in direct contact with the cylinder, at least on the surface that contacts the cylinder, the surface of the main body that is on the inner side in the canvas width direction from the both ears and does not directly contact the cylinder A surface property having a larger frictional force than that of the main driving cylinder is added to increase the frictional force between the canvas and the cylinder to compensate for a delay in driving synchronization of the cylinders other than the main driving cylinder and a lack of rotational speed.
[0026]
In order to increase the frictional force between the canvas and the cylinder, the surface of both ears of the canvas that is in direct contact with the cylinder surface needs to have a high coefficient of friction.
[0027]
The canvas is roughly classified into a woven canvas having a surface made of a woven fabric and a needle canvas in which a non-woven fabric layer of short fibers is bonded to the surface of the woven base fabric by needle punching or the like. Recently manufactured canvases include woven canvas and needle canvas woven fabrics and short fibers arranged on the surface, synthetic fibers such as polyester, polyamide, acrylic, polyolefin or polyphenylene sulfide (PPS), or synthetic resin monofilaments. It consists of
[0028]
The friction coefficient between a woven canvas or needle canvas made of a material such as polyester and a metal plate having sufficient surface smoothness was measured. As a result, the coefficient of static friction was 0.16 to 0.25 in a woven canvas using polyester monofilaments for warp and weft. Further, in a needle canvas in which a web of synthetic fiber staples was laminated by needle punching on a base fabric using polyester monofilaments for warp and weft, the coefficient of static friction was 0.18 to 0.30.
[0029]
As described in the examples, if the coefficient of friction of the ear part that is in direct contact with the cylinder is at least 1.5 times the coefficient of friction of the body part of the canvas that is in contact with the wet paper, it is not the canvas and the main drive system. It has been found that the effect of preventing slippage between the driven cylinder 2b or the freely rotating cylinder 2c and the canvas is preferable, and the following configuration is preferable.
[0030]
1) For the canvas, it is preferable that the canvas is flexible in order to maintain the adhesion to the cylinder because the frictional force is easily transmitted.
2) The resin coating amount is preferably as small as possible within the range where the elasticity of the resin film can be utilized.
3) From the viewpoint of adhesion durability of the resin, it is preferable that the resin fills the canvas texture or surface voids.
[0031]
However, if the amount of resin filling is large, the flexibility of the canvas is impaired. Further, when the resin film on the canvas is thick, the resin film is easily peeled off, and when the coating portion is thick, there is a possibility that the canvas may be wrinkled based on that portion. Therefore, it is desirable that not only the resin penetrates the entire canvas in the thickness direction but also the surface layer portion of the canvas is coated and impregnated so that a resin film is formed on the surface layer portion of the canvas.
[0032]
As long as the resin coating occupies most of the canvas surface, the resin film of the present invention is preferably in the range of 0 mm to 0.20 mm in terms of the increase in canvas thickness. As shown in FIG. 1, in a woven structure in which a warp 4 and a weft 5 on the paper contact surface side (first layer) and a weft 6 on the non-paper contact surface side (second layer) are woven into a weft double weave structure, In the case of a canvas having a resin coating 7 formed on the paper surface side, even if the increase in thickness is 0 mm, it occupies most of the surface 8 of the canvas, and the position in the thickness direction of the canvas warp knuckle 9 that defines the canvas thickness The resin coating 7 filled up to can transmit the frictional force to the cylinder without hindrance. However, if the resin coating 7 is on the inner side in the thickness direction than the warp knuckle 9, a sufficient friction force cannot be transmitted to the cylinder. If the increased thickness exceeds 0.20 mm, the risk of the resin film peeling off from the canvas increases, and the period of the anti-slip effect by the resin film is shortened.
[0033]
Apply the obtained resin as it is, or dilute with a solvent suitable for the target resin such as organic solvent and water, adjust the solid concentration and viscosity, and apply, dry and The target resin film can be formed by curing.
[0034]
As the resin to be used, a resin that is elastic even after coating and curing is preferable because the frictional force generally increases. In addition, a resin having high adhesiveness may be used from the viewpoint of durability.
[0035]
Resin used to satisfy these required properties is selected from resins such as urethane resin, silicone resin, epoxy resin, and commercial rubber adhesives such as chloroprene, textile processing, and nonwoven fabric binders. Available. In particular, a urethane-based resin is preferable because the resin film after application has elasticity and excellent adhesiveness. Silicone resins are preferred because they are excellent in the elasticity and heat resistance of the resin film.
[0036]
As another embodiment of the present invention, the surface of both ears that are in direct contact with the cylinder is imparted with a surface property having a greater frictional force than the surface of the main body. This is possible by arranging a thread with a large friction coefficient on the surface.
[0037]
For example, polyurethane spandex yarns with high elasticity can be stitched onto the canvas surface using yarns that are singly or twisted with yarns of other materials, woven together with canvas fabric yarns, It is possible to obtain the desired canvas by replacing the yarn constituting the woven fabric and weaving it to expose the polyurethane spandex yarn on the surface of the woven fabric.
[0038]
FIG. 2 shows a weft 10 having a high coefficient of friction in a weft double weaving structure comprising a warp 4, a weft 5 on the paper contact side (first layer) and a weft 6 on the non-paper contact side (second layer). FIG. 2 is a conceptual cross-sectional view of a canvas made of a weft-double woven fabric that is added to the fabric surface 8 by binding it with a woven structure different from the warp yarn 4 constituting the fabric.
[0039]
FIG. 3 shows a weft 10 having a high friction coefficient in a weft double weaving structure comprising a warp 4, a weft 5 on the paper contact side (first layer) and a weft 6 on the non-paper contact side (second layer). FIG. 4 is a conceptual cross-sectional view of different canvases made of woven fabrics that are woven and aligned with warp yarns 4a (the other side of the paper in FIG. 3) of a weft-woven weave structure.
[0040]
FIG. 4 shows a weft 10 having a high friction coefficient in a weft double weaving structure comprising a warp 4, a weft 5 on the paper contact side (first layer) and a weft 6 on the non-paper contact side (second layer). Is a conceptual cross-sectional view of still another canvas made of a weft-double woven fabric that is woven by replacing some of the warps 4 constituting the fabric.
[0041]
Furthermore, in the canvas, a multifilament system, a spun system, a crimped yarn, or a lot of fluffy and / or bulky yarn is exposed on the fabric surface of both ears in direct contact with the cylinder. If the resin is applied to the surface, the resin penetrates to the inside in the canvas thickness direction, and can be applied while remaining on the fabric surface without impairing the flexibility of the canvas, and the adhesive strength of the resin is also improved. Further, when a yarn having high elasticity such as spandex is used for the yarn, the elasticity of the woven fabric is added to the applied resin film, the adhesion to the cylinder is increased, and the frictional force is increased, which is preferable.
[0042]
In the canvas, it is inevitable that the warp yarns 4 are frayed due to friction at the ends of both ears of the canvas due to factors such as deviation and meandering during traveling. In particular, when the canvas automatic travel guide of the paper machine is a contact detection type of palm or the like, it is indispensable to consider contact wear with palm at the end of the canvas.
[0043]
Usually, the warp 4 and the wefts 5 and 6 are welded at the ear part of the woven canvas, but it is inevitable that the weld part peels off with the passage of time of use and the warp thread 4 at the ear part frays. For this reason, in the canvas, the end portion is ear-reinforced with resin. As the resin used for the ear reinforcement, epoxy, polyurethane, synthetic rubber, or the like is used. The resin is applied with a width of 2 to 3 cm from the end of the canvas and cured by hot air drying or the like. The resin used in this case is a resin capable of obtaining a sufficient hardness after curing in consideration of durability against abrasion. For this reason, the resin coating film 7 is made first in the portion where the ears are reinforced by the resin application, the resin to be newly applied does not penetrate, the adhesive force is insufficient, and it is easy to peel off during use.
[0044]
In the practice of the present invention, when resin is applied to add a surface property with a large frictional force, as shown in FIG. 5, for example, on the surface side 13 in contact with the cylinder 12 in the portion excluding the ear reinforcement portion 11. The resin film 14 is preferably formed by coating.
[0045]
Furthermore, in order to increase the frictional force between the canvas 15 and the cylinder 12, the resin film 14 applied and formed on the surface side 13 in contact with the cylinder 12 is thicker than the resin film in the ear reinforcement portion 11. It is preferable that the thickness of the resin coating film of the ear reinforcing portion 11 is not affected.
[0046]
In addition, the canvas body portion 17 that is in contact with the wet paper web 16 and does not come into direct contact with the cylinder 12 at the time of papermaking drying needs to have proper air permeability in order to promote drying of the wet paper web 16. Good surface smoothness that does not cause quality problems is required. Therefore, as a portion for imparting a surface property having a large frictional force to the surfaces of both ears of the canvas 15, for example, as shown in FIG. 5, it contacts the wet paper 16 during papermaking and directly contacts the cylinder 12. It is necessary to remove the canvas body portion 17 that is not to be used.
[0047]
Similarly, when the yarn 10 having a high coefficient of friction is provided in order to add a surface property having a large frictional force, the ear reinforcing portion 11 and the papermaking are used as the woven fabric portion on which the yarn 10 is provided. It is preferable to make the portion excluding the main body 17 of the canvas that is in contact with the wet paper web 16 and not in direct contact with the cylinder 12 during drying.
[0048]
According to the present invention, in one cylinder group of the drying section of the paper machine, at least one cylinder driving system is driven by a driving system that is not directly connected to the main driving cylinder by the mechanical connecting means. And / or providing a canvas capable of reducing paper-breaking troubles at the time of paper-making without causing problems in the quality of wet paper in a drying section of a paper machine that is configured to freely rotate. Is possible.
[0049]
In addition, about each test method concerning implementation of this invention, it is based on the following.
[0050]
1) Coefficient of friction
For the friction coefficient, a friction coefficient measuring device 20 shown in FIG. 6 is used. In this apparatus 20, a weight 22 is placed on a sample S on a contact member 21 of a fixed, chrome-plated metal plate, and the sample S is fixed, and a load W is applied in the vertical direction. In the state, when the pull string 23 tied with the weight 22 is pulled and traveled in the direction of the arrow through the pulley 24 (speed 50 mm / min), the frictional force F when the sample S starts to move is measured. Based on the friction force F and the load W (= 5 kg), the friction coefficient was calculated from the relational expression [friction coefficient (μ) = friction force (F) / load (W)]. As the sample S, a sample having a width of 10 cm (weft direction) and a length of 15 cm (warp direction) was used.
[0051]
2) thickness
It is measured with a thickness measuring instrument in accordance with JIS L-1096: 1999 “General Textile Testing Method”. The thickness of the resin film 14 was determined by subtracting the thickness of the canvas main body 17 before application of the resin from the thickness of the canvas 15 where the resin was applied. The measurement pressure was 14.7 kPa.
[0052]
[Example]
Next, Example 1 and Example 2 of the present invention will be described.
[0053]
Example 1
As shown in FIG. 7, a polyester monofilament is used for the warp 31, the weft 32 on the paper contact surface side (first layer) 35, the weft 33 on the non-paper contact surface side (second layer), and the weft 34 of the intermediate layer. A dryer canvas 30 woven into a weft triple weave having a cross-sectional structure is heat-set by a conventional method, cut to a predetermined width (750 cm), welded with a thermal iron, and the warp 31 is frayed. The epoxy resin is mixed with the amine-based curing agent at a specified ratio, applied to both ears with a width of 3 cm from the welded end portion, subjected to heat curing treatment in a hot air drying furnace, and the ear reinforcing portion 11 ( (See FIG. 5). Thereafter, a room temperature curing type silicone resin is applied to the paper contact side surface 35 (refer to the surface 13 in FIG. 5) from the welded canvas end in the canvas width direction to the canvas width direction from the boundary of the ear reinforcement portion 11 3 cm inside. At the time of 6 cm papermaking, it is applied to a width that does not contact the wet paper 16, dried and cured, and at least the ears that are in direct contact with the cylinder 12 on the surface side 13 that contacts the cylinder 12 have a surface property with a large frictional force. An added resin film 14 (see FIG. 5) portion was formed.
[0054]
The resin was impregnated from the position of the weft 32 on the paper contact side (first layer) in the woven structure shown in FIG. 7 to the inside of the canvas thickness direction beyond the weft 32 of the first layer. The thickness of the coated part (resin film 14) after drying and curing was 0.12 mm thicker than the canvas body part 17 not coated. Further, the coefficient of friction of the coated part (resin film 14) was measured and found to be 0.62, which was three times as large as the coefficient of friction of the canvas main body 17 not coated with resin.
[0055]
The canvas is tuned by detecting the rotational speed of the main drive motor and the single cylinder 2a driven by the main drive motor shown in FIG. 11 described above with a cylinder size of 800 cm wide and a diameter size of 183 cm. It was hung in a drying section of a cylinder upper and lower two-stage arrangement system composed of a total of seven cylinders, three cylinders 2b driven by a driven motor to be driven and three cylinders 2c that freely rotate. The paper making speed was 800 m / min, and paper making was performed for 100 days.
[0056]
In a conventional canvas of the same type as in Example 1 in which the surface property having a large frictional force is not added to both ears, the wet paper breaks due to unstable cylinder speed at least once every time the paper is produced. Although trouble occurred, when the canvas of Example 1 was used, the paper could be drawn without any trouble of wet paper breakage due to unstable cylinder speed. Also, there was no particular problem in the paper quality of the product, such as paper thickness variation due to slippage between the canvas and the synchronous drive cylinder 2b or the freely rotating cylinder 2c.
[0057]
[Example 2]
As shown in FIG. 8, a warp 41, a weft 42 on the paper contact side (first layer) and a weft 43 on the non-paper contact side (second layer) are woven into a double weave structure using polyester monofilament, The web layers 44 and 45 in which polyamide fiber staples and acrylic fiber staples are mixed are laminated on both sides of the base fabric heat-set by the above method, and entangled with the base fabric by needle punching. A needle canvas 40 having a structure as shown was created.
[0058]
From the paper contact surface side 46 of the needle canvas 40, a 15% solid solution of acrylic copolymer resin is applied, dried and cured, cut into a predetermined width (750 cm), and the ends are welded with a thermal iron. The fray was stopped. After that, urethane resin of dimethylmethane diisocyanate (MDI) polyether prepolymer is mixed with polyol at a specified ratio, and the resin is applied at a width of 9 cm from the welded end in the canvas width direction, and then dried and cured. Thus, at least ear portions 11 that have a surface property with a large frictional force are formed on both ear portions that are in direct contact with the cylinder 12 on the surface side 13 that contacts the cylinder 12.
[0059]
The resin was impregnated to the middle of the web layer 44 on the paper contact side 46. The thickness of the coated part after drying / curing was 0.08 mm thick compared to the uncoated part. Further, the coefficient of friction of the coated portion was measured and found to be 0.43, which was 1.5 times the friction coefficient of the needle canvas main body not coated with resin.
[0060]
This needle canvas 40 has a cylinder size of 800 cm in width and 183 cm in diameter, the upper five and the lower four, of which the two upper and two lower cylinders are freely rotating, and the remaining five cylinders Was placed in a drying section of a cylinder upper and lower two-stage arrangement system that is directly connected to a gear train and driven. The paper making speed was 800 m / min, and paper making was performed for 100 days.
[0061]
In a conventional needle canvas of the same type as in Example 2 that does not have a special surface property with a high frictional force at both ears, the cylinder speed is one or more times at a rate of 5 degrees for every 10 degrees of the sheeting opportunity. Wet paper breakage due to instability occurred, but when the needle canvas of Example 2 was used, paper cutting could be performed without any paper breakage trouble due to unstable cylinder speed. Also, the paper quality of the product was not particularly problematic as in Example 1.
[0062]
【The invention's effect】
According to the papermaking dryer canvas of the present invention, on the surface of both ears that are in direct contact with the cylinder, on the surface of the canvas that is in contact with the cylinder, the inner side in the canvas width direction from the both ears and directly in contact with the cylinder Because a paper machine dryer canvas with a surface property that has a higher frictional force than the surface of the main body is not used, a drying section of a paper machine in which one canvas or a pair of canvases on each of the upper and lower sides runs around In one cylinder group, the paper drive system is configured such that at least one or more cylinders are driven by a drive system that is not directly connected to the main drive cylinder by the mechanical connection means and / or is freely rotated. In the drying section of the machine, slip between the cylinder and the canvas can be greatly reduced, resulting in wet paper quality problems. Without Rukoto, it has become possible to reduce the cross-sectional paper trouble when out paper making.
[Brief description of the drawings]
FIG. 1 is a conceptual cross-sectional view of an example of a paper making dryer canvas in which frictional force is increased by the resin coating film of the present invention.
FIG. 2 is a conceptual cross-sectional view of an example of a woven structure of a papermaking dryer canvas using yarns with high frictional force according to the present invention.
FIG. 3 is a conceptual cross-sectional view of another example of a woven structure of a dryer canvas for paper making using a yarn having a high frictional force according to the present invention.
FIG. 4 is a conceptual cross-sectional view of still another example of a woven structure of a papermaking dryer canvas using a yarn having a high frictional force according to the present invention.
FIG. 5 is a front view of a main part of the papermaking dryer canvas according to the embodiment of the present invention.
FIG. 6 is a schematic configuration diagram of a friction coefficient measuring device for a papermaking dryer canvas.
FIG. 7 is a schematic cross-sectional view of a woven structure in a papermaking dryer canvas of Example 1 of the present invention.
FIG. 8 is a conceptual cross-sectional view of a woven structure in a papermaking dryer canvas of Example 2 of the present invention.
FIG. 9 is a schematic configuration diagram of a drying unit in a single row cylinder type paper machine in which one canvas is hung in a cylinder arranged in a single row.
FIG. 10 is a schematic configuration diagram of a drying section in a paper machine of an upper and lower canvas type in which a set of upper and lower canvases travels around.
FIG. 11 is an example of a paper machine drying section that is the subject of the present application in an upper and lower canvas system.
[Explanation of symbols]
1 Dryer canvas for papermaking
2 cylinders
2a Cylinder driven by main motor
2b Cylinder driven by driven motor
2c Free rotation cylinder
3 guide rollers
4 Warp
4a Warp yarns that are woven together with yarns with a high coefficient of friction
5,6 weft
7 Resin coating
8 Fabric surface
9 Knuckles
10 Yarn with high coefficient of friction
11 Ear reinforcement
12 cylinders
13 Surface side in contact with cylinder
14 Resin film
15 Dryer canvas for paper making
16 Wet paper
17 canvas body
20 Friction coefficient measuring device
30 Dryer canvas for paper making
31, 41 Warp
32, 42 Warp on the paper contact side (first layer)
33, 43 Weft on the non-paper contact side (second layer)
34 Middle layer weft
35, 46 Paper side
40 Needle canvas
44,45 web layer

Claims (7)

In one dryer cylinder group of a drying section of a paper machine in which one dryer canvas or a pair of dryer canvases on each of the upper and lower sides circulates, at least one dryer cylinder is a main drive dryer cylinder. A paper machine dryer canvas used in a drying section of a paper machine driven by a drive system not directly coupled by a mechanical coupling means and / or configured to freely rotate,
Except for the surface of both ears that are in direct contact with the dryer cylinder on the side of the dryer canvas that contacts the dryer cylinder, and the surface of the body that does not directly contact the dryer cylinder, the dryer canvas at the end of the dryer canvas of the portion excluding the ear reinforcement portion imparted with wear resistance against contact wear of palm as a contact-type detection of the automatic travel guides, wherein a drier canvas width inward from both ears, the body surface A paper making dryer canvas characterized by the addition of surface properties with greater frictional force. 2. The dryer canvas for papermaking according to claim 1 , wherein the means for adding a surface property having a large frictional force to the surfaces of both ear portions that are in direct contact with the dryer cylinder is to apply a synthetic resin. The paper making dryer canvas according to claim 2 , wherein the synthetic resin is polyurethane. The paper making dryer canvas according to claim 2 , wherein the synthetic resin is a silicone-based resin. The paper making dryer canvas according to any one of claims 2 to 4 , wherein the synthetic resin is applied to a thickness in the range of 0 mm to 0.20 mm. Yarn obtained by twisting a yarn with a high frictional force alone or with a yarn of another material at a site where a surface property with a high frictional force is added to the surfaces of both ears that are in direct contact with the dryer cylinder The yarn is bound on the surface of the dryer canvas, or woven with the yarn constituting the fabric of the dryer canvas, or is replaced with the fabric yarn of the dryer canvas and is woven into the surface of the fabric on the both ears. The paper making dryer canvas according to any one of claims 1 to 5 , wherein In one dryer cylinder group of a drying section of a paper machine in which one dryer canvas or a pair of dryer canvases on each of the upper and lower sides circulates, at least one dryer cylinder is a main drive dryer cylinder. A paper machine dryer canvas used in a drying section of a paper machine driven by a driving system not directly coupled by a mechanical coupling means and / or configured to freely rotate,
  At least on the surface of the dryer canvas that contacts the dryer cylinder, on the surface of both ears that are in direct contact with the dryer cylinder, from the inner surface of the dryer canvas in the width direction of the dryer canvas and not directly on the dryer cylinder The surface property with high frictional force, the yarn made of material with high frictional force alone, or the yarn twisted together with the yarn of other material is bound to the surface of the dryer canvas, or the dryer canvas A woven fabric canvas for papermaking, wherein the woven fabric yarn is arranged and woven together or is replaced by a woven fabric yarn of a dryer canvas and woven to be exposed on the fabric surface of the both ears.

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