JP2003336187A - Drier canvas for papermaking machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drier canvas for papermaking machines suitably usable for drying part of the papermaking machine as applications in which high quality appearance and level are required, e.g. wood-free paper or raw paper for coating, having excellent flexibility in a warp direction and excellent stiffness in a weft direction and excellent surface smoothness, capable of applying to a drying part of a wide-width and high-speed paper-making machine having ≥9 m canvas width size and ≥1,500 m/min papermaking max speed and having a good shape-retaining property and traveling stability. <P>SOLUTION: In the drier canvas for papermaking machine woven by using a warp and a weft, a synthetic monofilament having a cross section shape comprising continuing one curved line m or continuing two curved lines k and l or one line (p) and continuing one curved line (n), internally making contact with a trapezium in which a thick direction dimension (a) is smaller than a width direction dimension (b) and not having a linear part in the thickness direction and having a cross section larger than a regular elliptical area internally making contact with the square is used as a warp 11 and a packing ratio of the warp 11 is controlled to 100 to 175%. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a dryer canvas for a papermaking machine used in the drying section of a paper machine. In particular, it has excellent shape retention characteristics and running stability that can be applied to wide and high-speed paper machines, and surface smoothness suitable for applications that require a high level of quality, The present invention relates to a dryer canvas for a papermaking machine having flexibility and rigidity in the weft direction.

[0002]

2. Description of the Related Art A dryer canvas used in the drying section of a paper machine presses wet paper to a heated cylinder to dry it. However, if the pressing force applied to the wet paper is not uniform, uneven drying occurs. Paper quality will be impaired. In particular, in applications that require high quality standards such as high-quality paper and papermaking for coating base paper, not only quality defects such as paper marks of wet paper do not occur, but also the flow direction of wet paper. And the demand for uniform drying in the width direction is high. Therefore, it is necessary to uniformly contact the wet paper web with the cylinder, and it is possible to maintain uniform adhesion and pressing force with the wet paper web in the flow direction and the width direction even under conditions of wide width and high speed. Desired.
Therefore, it is necessary to have both good strength in the warp direction and rigidity in the weft direction while having good surface smoothness and flexibility in the warp direction.

On the other hand, in recent years, the width and speed of paper machines have become wider, and, for example, the canvas width dimension is 9 m or more, and the papermaking speed max.
Although it has a track record of more than 1,500 m / min., It is required to develop a dryer canvas that can ensure stable operation of the paper machine in response to such widening and speeding up of the paper machine. In addition to improving the flexibility of the warp direction and the rigidity of the weft direction,
It is becoming more important to improve shape retention characteristics and running stability.

On the other hand, as the structure of the drying section of a multi-cylinder dryer for papermaking, the conventional upper and lower canvas system in a dryer having an upper and lower two-stage arrangement, a single run canvas system as an improvement plan thereof, and a further improvement plan thereof are proposed. The berlan method (a trademark of Beloit, USA) and the simran method (a trademark of Valmet, Finland), in which the cylinders are arranged in a single row, have been proposed, and improvements have been made to increase the papermaking speed. . In the single-run canvas method, on the lower cylinder, and in the Berlan method, on the suction roller provided between the cylinders, because the wet paper runs on the outer periphery of the dryer canvas, the upper cylinder part and the lower cylinder part are Causes a difference in peripheral speed corresponding to the thickness of the canvas, which causes
For example, when a dryer canvas which has been conventionally used in a drying section having a dryer with a two-stage upper and lower arrangement is used, tension and slack of tension applied to the wet paper as the wet paper travels is repeated, resulting in the wet paper. There was also a possibility that it would adversely affect, or seriously, a defect such as a paper break might occur. Therefore, it is indispensable that the thickness of the canvas is thin particularly in a single-run canvas system for performing high-speed papermaking or a drying unit in which the cylinders are arranged in a single row.

As one of the methods for improving the flexibility of the dryer canvas in the warp direction, a method of using a monofilament having a fineness for the warp forming the canvas is considered, and further, in order to increase the rigidity in the weft direction, A method of using a monofilament having a large fineness as the weft thread forming the canvas is considered. Therefore, if a finer monofilament is used for the warp and a thicker monofilament is used for the weft, it is considered that it is possible to improve the flexibility in the warp direction while ensuring the rigidity in the weft direction. , When the rigidity of the warp is insufficient with respect to the rigidity of the weft, the bond due to the intersection at the intersection of the warp and the weft is loose,
There is a risk that the restraint between the threads will be weakened and the displacement resistance of the canvas will be reduced.

Here, the "deviation resistance" is a characteristic that represents the resistance of the dryer canvas to oblique deformation. If the dryer canvas is deformed in the diagonal direction, the dimensional change in the width direction and the length direction becomes large, and the problem that the shape required for the dryer canvas cannot be maintained or running stability cannot be ensured occurs. Become. Therefore, it is necessary to select such that the relationship between the fineness of the warp and the weft and the relationship between the rigidity of the warp and the rigidity of the weft are appropriate.

As another method for improving the flexibility of the dryer canvas in the warp direction, the warp forming the canvas has a so-called flat cross section having an appropriate thickness dimension and a width dimension larger than the thickness dimension. There is a method of using a monofilament (hereinafter referred to as a “quadrangular monofilament having a cross section”).

In addition, in order to flatten the warp yarns constituting the dryer canvas, a considerable high pressure is applied to the dryer canvas under heating to make a thick yarn having a circular cross section into a flat cross section and flatten the knuckle portion. (JP-A-58-4
No. 1992), the knuckle portion woven by threads having a circular cross section is ground to be flattened.
No. 798 gazette) technology, etc., but requires equipment for generating a high pressing force under heating, and stains such as paper powder and filler easily adhere to the rough surface of the polished warp surface to prevent stains. There was an inferior problem.

By the way, when a monofilament having a quadrangular cross section is used for the warp, flexibility in the warp direction can be obtained.
It is known that there are the following problems.

That is, with the recent high demand for paper quality and high speed of paper machines, while maintaining high surface smoothness and small thickness, a wide air permeability range including low air permeability. In order to achieve the above, there is a limit to the correspondence only with the densification of the weft and the weaving design in which the warp floats for a long time, and in order to respond to the high speed and wide width of the paper machine, In order to reinforce rigidity and shape retention characteristics, it is necessary to increase the density of warp yarns as well.
%, Preferably 125%, but it is also necessary to set it in a high range, but in that case, it becomes difficult to ensure a desired high range of filling rate due to interference between adjacent square monofilaments in cross section. The deviation resistance cannot be improved, and it is difficult to further improve the shape retention characteristics and the running stability.

Further, if the filling rate is increased to a certain degree or more, even if a woven fabric having a good surface property is selected, the flat surface of the quadrangular monofilament and the canvas surface cannot be maintained in parallel {Fig. 6 (A )}, A corner of the quadrangular cross section of the warp 70 appears on the canvas surface 71 on a part of the surface of the canvas, which affects the improvement of the surface property of the canvas and affects the handling of the warp during weaving. It has been found that there are problems such as a decrease in weaving efficiency.
Applicants have, for example, a warp yarn having a thickness dimension × width dimension of 0.3.
It has been empirically found that, when a 0 mm × 0.55 mm square quadrangular polyester monofilament is used, the practical upper limit is around a warp filling rate of 125%.

The warp filling rate is a percentage per unit length expressed by the product of the warp density in the width direction of the fabric and the width dimension of the warp cross section in the fabric width direction.

[0013]

In view of the above problems,
The present invention, for example, papermaking of high-quality paper or base paper for coating,
An object of the present invention is to provide a dryer canvas for a papermaking machine, which has good surface smoothness that can be suitably used in applications requiring a high quality level, and has both flexibility in the warp direction and rigidity in the weft direction. To do.

Further, the thickness is applicable to the dry section of the single run canvas system or the type in which the cylinders are arranged in a single row, and, for example, the canvas width dimension is 5 m to 9 m.
m, further 9 m or more, machine speed max 1,500 m / min.
An object of the present invention is to provide a dryer canvas for a papermaking machine, which is applicable to the above wide and high speed paper machines and has excellent shape retention characteristics, running stability, and a wide air permeability adjustment range.

[0015]

A dryer canvas for a papermaking machine of the present invention is a dryer canvas for a papermaking machine made of a synthetic fiber woven fabric, in which a warp is inscribed in a quadrangle having a thickness smaller than a width and is continuous. Or a synthetic fiber monofilament having a cross-sectional shape consisting of a straight line and a continuous curve without a straight line portion in the thickness direction and having a cross-sectional area larger than the area of a regular ellipse inscribed in the quadrangle. The warp filling rate is within the range of 100% to 175%.

Further, in the dryer canvas for a papermaking machine of the present invention, the synthetic fiber monofilament used for the warp has a thickness dimension × width dimension of 0.25 mm to 0.40 mm ×
It is characterized by having a cross-sectional shape without a straight line portion inscribed in a quadrangle in the range of 0.35 mm to 0.80 mm in the thickness direction.

In addition, in the dryer canvas for a papermaking machine of the present invention, the monofilament used for warp and having a cross-sectional shape without a straight line portion in the thickness direction has a thickness dimension: width dimension ratio of 1: 1.25-1. : Inscribed in the rectangle within the range of 2,
In addition, it has a cross-sectional area in the range of more than 0.79 times and less than 0.96 times the cross-sectional area of the inscribed quadrangle.

Further, the dryer canvas for a papermaking machine of the present invention uses a monofilament having a high dry heat shrinkage ratio in at least one layer of the weft yarns, and has a warp filling ratio of 130% to 130%.
It is characterized by being set within the range of 175%.

Further, the dryer canvas for a papermaking machine of the present invention has a weave design of weft double twill weave, and has a diameter of 0.40 mm to 0. Using a circular cross-section monofilament within the range of 80 mm, the thickness dimension is 1.30 mm ~
It is characterized by being within a range of 1.80 mm.

Furthermore, the dryer canvas for a papermaking machine of the present invention comprises a weft single-fold twill weave structure in which the warp floats long at least on the paper-contacting surface, and the weft has a diameter of 0.60 mm to 1 mm. A circular cross-section monofilament within the range of 0.00 mm is used, and the thickness dimension is from 1.00 mm to
It is characterized by being within a range of 1.60 mm.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The dryer canvas for a papermaking machine of the present invention is a synthetic fiber woven fabric in which synthetic fiber yarns are used for warp and weft.

As the synthetic fiber yarn, polyester fiber such as PET or PBT, polyamide fiber such as nylon 6, nylon 46, nylon 66, polyolefin fiber such as polypropylene, or PPS having excellent heat resistance is used.
It is possible to use synthetic fiber yarns made of, for example, PEEK, or the like, or synthetic fiber yarns mainly composed of them, and to use them for warp and / or weft alone or in combination. Polyester fibers such as PET and PBT are preferable from the viewpoint of dimensional stability, wear resistance, bending fatigue resistance, etc., and PPS and PEEK are preferable from the viewpoint of heat resistance.

As the weave design, weft 1 double weave design generally used for dryer canvas, and weft 1 double weave, weft 2.5 double weave or weft 3 or more weave or more weaving weave, A woven structure such as heavy or double-ply is applicable. For example, weft double weave, weft 2.5 double weave, or 1 / th of weft triple weave
3 regular italic and 1/3 broken italic are preferably applicable.

Further, it is preferable that the warp has a floating structure to improve the flatness of the surface and increase the contact area with the wet paper in the canvas flow direction, that is, the warp direction. A floating weft double or weft single twill weave design is preferred. The woven design in which the warp floats for a long time refers to a design in which the warp straddles two or more wefts, and in the double weave twill weave design in which the warp floats for a long time on at least the paper-contacting surface, the As shown in (A) and (B), a 2/2 regular italic pattern or a 2/2 broken italic pattern in which a large amount of warp appears on the surface of the paper-contacting side {Fig. 1 (A)}, 3/3 regular italic pattern and 3 / 3 torn italics {Fig. 1 (B)}, 3/3 steep italics and 3
A woven fabric such as 3/4 suddenly torn oblique line (FIG. 1 (B)) can be used. In addition, as shown in FIGS. 1C and 1D, a large amount of warp is exposed on the surface of the paper-contact side 2 /
1 regular italic or 2/1 broken italic {Fig. 1 (C)}, 3/1 regular italic or 3/1 broken italic {Fig. 1 (D)}, 3/1 steep italic or 3/1 It is possible to use a single weft weave design, such as a sharply torn twill {Fig. 1 (D)}.

A dryer canvas for a papermaking machine according to the present invention is a dryer canvas for a papermaking machine made of a synthetic fiber woven fabric, in which a warp is inscribed in a quadrangle having a thickness smaller than a width and a continuous curve or straight line. And a synthetic fiber monofilament having a cross-sectional shape consisting of continuous curves and having no straight portion in the thickness direction and having a cross-sectional area larger than the area of a regular ellipse inscribed in the quadrangle, and the warp filling rate is 100. % To 175%. This structure has a warp filling rate of 125% to
It is more effective in the range of 175%.

Here, "inscribed in a quadrangle having a dimension in the thickness direction smaller than the dimension in the width direction and having a continuous curve, or a straight line and a cross-sectional shape having no straight line portion in the thickness direction composed of continuous curves, and , A synthetic fiber monofilament having a cross-sectional area larger than the area of a mathematically defined regular ellipse inscribed in the quadrangle "means a cross section having a minor axis a and a major axis b as shown in FIG. 2 (A). Does not include a regular elliptical shape that is mathematically defined, and in addition, the cross-sectional shape obtained by smoothly chamfering the four corners of the quadrangular cross-section has a straight line portion in the thickness direction, so the "thickness of the present invention “Cross-sectional shape having no straight portion in the direction”, and has a cross-sectional shape as shown in FIGS. 2B, 2C and 2D.
That is, when the outline is composed of continuous curves, it is composed of one or two continuous curves, and when the outline is composed of straight lines and continuous curves, one straight line and It has a cross-sectional shape composed of one continuous curve. Further, it is preferable that the outer shape line does not curve inward and the outer shape does not have a recess.

That is, FIG. 2B is composed of one curve m inscribed in a quadrangle having a width dimension X and a thickness dimension Y, and a curve representing the outer shape of the quadrangle of the circumscribed quadrangle. Each one point included on each side of, for example, the midpoint c,
It passes through c ′, d, d ′, and is closer to the side of the circumscribed quadrangle than the mathematically defined regular ellipse of FIG. 2 (A),
A cross-sectional shape having a larger cross-sectional area. Alternatively, FIG. 2C is composed of two curves k and l which are inscribed in a quadrangle having the width direction X and the thickness dimension Y and whose contours are continuous curves in cross section, and the curve k is a circumscribed quadrangle. 1 point included in 3 sides of 4 sides of, for example, 1 point included in 3 sides of 4 sides of the circumscribed quadrangle, for example, a midpoint, passing through the midpoints c, d, c ′ c, d ', c'
2A, which is closer to the side of the circumscribed quadrangle and has a larger cross-sectional area than the mathematically defined regular elliptical shape of FIG. In addition, FIG.
Similar to FIG. 2B, one straight line p is provided at a position overlapping with one curve n and the side (long side) in the width direction of the circumscribed quadrangle.
2A, which is closer to the side of the circumscribed quadrangle and has a larger cross-sectional area than the mathematically defined regular ellipse of FIG. 2A. In this case, the length dimension Z of the straight line portion p is 1/2 of the width direction dimension X.
~ 3/4 is preferred.

Hereinafter, in the present invention, these shapes are abbreviated as "cross-sectional shapes having no straight line portion in the thickness direction".

According to the present invention, by using the monofilaments 21 to 23 having the above "cross-sectional shape having no straight portion in the thickness direction" for the warp of the canvas, for example, as shown in FIG. The smooth curved surface shape of the side surface having no straight portion in the direction effectively acts, and the side surfaces of the adjacent monofilaments, which have conventionally been a problem when the warp 70 shown in FIG. Solves the problem that it is difficult to secure a desired high warp filling rate by interfering with each other.

As described above, the monofilament having a "cross-sectional shape having no straight portion in the thickness direction" used for the warp yarn of the dryer canvas of the present invention does not include a mathematically defined regular elliptical cross-section, and its outer shape. Is closer to the circumscribed quadrangle, the cross-sectional area of the circumscribed quadrangle is X (cross sectional area = X
Y)> (the cross-sectional area of “the cross-sectional shape without a straight line portion in the thickness direction”)> (the cross-sectional area of a mathematically defined regular cross-sectional ellipse = πXY / 4≈0.79XY), and mathematically It has a larger cross-sectional area than the regular elliptical monofilament defined in. Therefore, the strength of each yarn can be maintained high, and the strength of the dryer canvas in the warp direction can be maintained high.

The range of the cross-sectional area of the monofilament having the "cross-sectional shape having no straight portion in the thickness direction" used for the warp yarn of the dryer canvas of the present invention is less than the cross-sectional area (XY) of the circumscribing quadrangle as described above, The range exceeds the cross-sectional area (≈0.79XY) of a regular elliptical system inscribed in the quadrangle, but a preferable range is a cross-sectional area exceeding 0.79XY and 0.96XY or less, and more preferable range is The minimum value is 0.81XY and the maximum value is 0.89XY.

That is, as a sectional shape having a sectional area corresponding to the minimum value, for example, when the ratio of the thickness dimension Y and the width dimension X of the circumscribed quadrangle is 1: 1.25,
The lower side (or upper side) in the thickness direction of the cross section is a regular elliptical shape that is mathematically defined, and the upper side (or lower side) in the thickness direction is the two corners of the upper side (or lower side) of the circumscribed rectangle. It is possible to exemplify a cross-sectional shape having a cross-sectional area corresponding to a smoothly chamfered shape with a radius corresponding to ½ of the thickness dimension Y. Further, as a cross-sectional shape having a cross-sectional area corresponding to the maximum value, for example, when the ratio of the thickness dimension Y and the width dimension X of the circumscribed quadrangle is 1: 2.0, the circumscribed quadrangle is 4
A cross-sectional shape having a cross-sectional area corresponding to a shape in which a corner is smoothly chamfered with a radius corresponding to ½ of the thickness dimension can be exemplified. Alternatively, for example, in the cross-sectional shape shown in FIG. 2 (C), a higher-order function (for example, Y =
Z · X ^W , where Z is a real number and w is a natural number) and one continuous curve k can be expressed, and another continuous curve k that can be expressed by a higher-order function passing through the midpoints c, d and c ′ A cross-sectional shape having an outer shape composed of the curve 1 can be exemplified.

When a monofilament having a cross-sectional shape having no straight line portion in the thickness direction having the range of the cross-sectional area illustrated above is used as a warp of a canvas, a circumscribed quadrangle having at least the same strength per warp is used. Since it is possible to secure the range of more than 79% and 96% or less of the tenacity, the filling rate of the warp is 1/0. A range of more than 79 times and less than 1 / 0.96 times, that is, 130% or more and less than 158%, or 137% or more and less than 165%, or 130% or more, 1
If the warp filling rate is set within the range of less than 65%, which corresponds to the cross-sectional area ratio with the circumscribing quadrangle, it is possible to achieve the same warp direction strength as when a monofilament having a circumscribing quadrangular cross-sectional shape is used for the warp. Becomes

Further, it is preferable that the strength per warp of a circumscribed quadrangle of at least 81 is made of the same material.
Since it is possible to secure the range of not less than 89% and not more than 89%, the filling rate of the warp is 1 / 0.89 times or more that of the monofilament having a circumscribed quadrangular cross section, as in the above.
/0.81 times or less range, that is, 140% or more, 1
A monofilament having a circumscribed quadrangular cross-sectional shape can be obtained by setting a warp filling rate corresponding to the cross-sectional area ratio with the circumscribed quadrangle within the range of 54% or less, or 146% or more and 160% or less, or 140% or more and 160% or less. It is possible to achieve the same tenacity in the warp direction as when the warp yarn is used.
Further, if the warp filling rate is set to a range exceeding 160%, it is possible to make the warp direction stronger than in the case of using a monofilament having a circumscribed quadrangular cross-sectional shape for the warp.

The upper limit of the warp filling rate is set to 175%, depending on the woven structure to be applied and the rigidity of the monofilament warp, when the warp filling rate is higher than this, the warps overlap and the surface smoothness that can be practically used as a canvas is obtained. Because it will be difficult to obtain.

In the practice of the present invention, the thickness dimension × width dimension of the circumscribed quadrangle inscribed with the "cross-sectional shape having no linear portion in the thickness direction" monofilament used for the warp is 0.2.
It is within the range of 5 mm to 0.35 mm × 0.40 mm to 0.70 mm. Furthermore, it is preferable that the ratio of the thickness dimension to the width dimension of the circumscribed quadrangle is within the range of 1: 1.25 to 1: 2. The upper limit of 1: 2 is to prevent the number of warp yarns in the canvas width direction from decreasing and the tension load per warp yarn during weaving and during use becoming excessive. A dryer canvas made of monofilament warp and weft is inferior in cushioning properties to those made of multifilament or spun yarn, so the tension in the warp direction at the time of use is set higher than those canvases, and wet paper There is a tendency to improve the adhesiveness of the wet paper to improve the efficiency of drying the wet paper, and in some cases, a gearless dryer is installed in the drying section of the paper machine. In such a case, the tension load max.
The standard is 3 kg / cm, but in order to ensure stable operation and durability in response to warp wear and thermal deterioration, it is necessary to consider so that the tension load per warp is reduced. On the other hand, "a cross-sectional shape with no straight part in the thickness direction"
In order to effectively exhibit the flatness in the cross-sectional width direction of
The lower limit is 1: 1.25.

As the weft yarn, a monofilament is used at least on the paper contact side and / or on the non-paper contact side. The cross-sectional shape of the weft thread may be a circle, an ellipse, a polygon such as a triangle, a square, a rectangle, a quadrangle, a hexagon, an octagon, or a shape obtained by partially modifying these shapes. Other wefts include fine filament monofilaments, multifilament yarns, spun yarns of aligned or twisted yarns, and covered yarns having a coiled or coiled core-sheath structure. However, from the viewpoint of preventing dirt from adhering to the canvas due to paper powder or filler and removing the adhered dirt, it is preferable that the weft yarn on the paper contact side and the weft yarn on the opposite paper side are made of monofilaments.

Further, the dryer canvas for a papermaking machine of the present invention uses a monofilament having a high dry heat shrinkage rate in at least one layer of the weft, and the filling rate of the warp is 130%.
It is characterized in that it is within the range of ˜175%.

In order to increase the filling rate of the warp threads, in addition to setting the warp density at the time of weaving, processing conditions such that the shrinkage amount in the weft direction at the time of heat setting processing increases and weft threads having a high dry heat shrinkage rate are selected. To use. When using a weft having a high dry heat shrinkage, it is used for at least one layer of the weft. The filling rate of the warp can be increased by using it for all the weft layers. Further, it is preferable to use it for the weft yarn on the paper-contacting surface side in order to increase the contact area with the wet paper. When a weft yarn having a high dry heat shrinkage is used, a warp filling ratio of 130% to 175%, preferably 140% to 175%, and more preferably 150% to 175% can be realized. Become.

In the practice of the present invention, a monofilament having a high dry heat shrinkage used for a weft is 1 at 160 ° C.
2% to 26%, range of 14% to 30% at 180 ° C, more preferably 12% to 22% at 160 ° C, 1
It has a dry heat shrinkage ratio in the range of 14% to 24% at 80 ° C., and is generally available for a dryer canvas. For example, as the polyester monofilament, PX-405 manufactured by Shakespeare is commercially available. Further, as the PPS monofilament, there is one disclosed in JP-A-5-195318.

In the practice of the present invention, the monofilaments used for the weft yarns are weft double weave, weft 2.5 double weave or weft 3
In the case of a weave design of a heavy weave or more, for example, a circular monofilament having a cross section having a diameter dimension of 0.30 mm to 1.20 mm can be used for each of the paper contact side weft and / or the non-contact paper side weft. However, it is desirable to use a monofilament having a circular cross section whose diameter is within the range of 0.40 mm to 0.80 mm with respect to the size range of the warp. The diameter dimension is 0.40 mm to 0.80 mm.
12 wefts / double / 2.54c for the weft size range
m to 39 lines × double / 2.54 cm, preferably 1
3 x 2 / 2.54 cm to 25 x 2 / 2.54c
Weft density in the range of m is applicable.

In the case of a weft single-weave weave design, for example, a circular monofilament having a circular cross section with a diameter of 0.40 mm to 1.50 mm can be used as the weft, but the diameter of the weft is not more than 0. It is desirable to use a monofilament with a circular cross section in the range of 60 mm to 1.00 mm,
Further, with respect to the size range of the weft having a diameter of 0.60 mm to 1.00 mm, it is within a range of 12 threads / 2.54 cm to 35 threads / 2.54 cm, preferably 15 threads / 2.54 c.
A weft density within the range of m to 30 yarns / 2.54 cm can be applied.

Needless to say, the size and / or the density of the weft may be different between the weft yarn on the paper contact side and the weft yarn on the opposite paper side.

The lower limit of the above weft density is to satisfy the required surface smoothness, rigidity in the weft direction, running stability, shape retention and so on, and to obtain the necessary upper limit of the air permeability range. Is the lower limit of. Further, the upper limit of the weft density is obtained from the upper limit of the number of wefts that can be arranged in the canvas flow direction based on the minimum value in the dimensional range of the warp and the weft. In order to achieve such a high weft density, tension conditions and temperature conditions during weaving and processing are appropriately set appropriately so that the shrinkage amount in the warp direction during heat setting processing increases. Furthermore, for example, a monofilament having a high dry heat shrinkage ratio can be selected and used for the warp.

In the present invention, a monofilament having a "cross-sectional shape having no linear portion in the thickness direction" is used for the warp, and the warp filling rate is 100% to 175% (preferably 125% to 17).
5%), and using a weft having a higher dry heat shrinkage, 130% to 175% (preferably 140% to
175%), it is possible to increase the
In combination with the set range of the weft density, good surface smoothness and a wide air permeability range can be achieved, and at the same time, rigidity in the canvas width direction can be secured. That is, due to the high warp filling rate and the high weft density, it is possible to realize a lower air permeability than ever before. Further, even when a low weft density is taken in order to obtain a high air permeability range, the warp filling rate is high, so that the surface smoothness can be favorably maintained. In addition, the density of the contact points on the surface of the wet paper web that comes into contact with the wet paper web becomes high, and the wet paper web can be pressed uniformly, so that unevenness in drying the wet paper web can be further reduced.

The rigidity in the width direction of the canvas is generally improved as the size of the weft in the thickness direction of the canvas is increased. However, in the present invention, a monofilament having a "cross-sectional shape having no straight portion in the thickness direction" of the warp is used as its major axis. By arranging so that the direction is the width direction of the canvas, the thickness direction dimension of the warp can be made smaller than the case where a circular cross-section monofilament having an equivalent cross-sectional area is used for the warp. Since the thickness of the weft in the thickness direction can be increased within the range of the length, the rigidity in the canvas width direction can be improved accordingly.

Further, according to the present invention, by using a monofilament having a "cross-sectional shape having no straight line portion in the thickness direction" for the warp, the filling rate of the warp is set to be high so that the warps adjacent to each other in the width direction of the canvas can be sufficiently formed. Since it is configured so as to be in close contact, it has the effect of reducing the degree of freedom with respect to the bending of the canvas in the width direction, and in combination with the rigidity of the monofilament weft having the above diameter dimension range, the warp has a circular cross section or a cross section. The rigidity in the width direction can be improved as compared with the case where the quadrilateral monofilament is used. As a result, it becomes possible to obtain rigidity in the width direction that can meet the requirement that the canvas width dimension is 9 m or more.

Further, according to the present invention, when the warp having the "section having no straight portion in the thickness direction" comes into contact with the weft having a circular section, the section having a smooth curved surface effectively acts. The thickness of the canvas is reduced by utilizing the fact that the warp can be deeper in the intersecting portion with the weft than in the case where the warp having the quadrangular cross section abuts on the weft having the circular cross section.

That is, for example, when a contact force P based on a tension T per unit length applied to a weft is applied, a warp having a quadrangular cross section abuts on a weft having a circular cross section, and the above-mentioned "straight line in the thickness direction". When a warp having a “sectionless cross-sectional shape” comes into contact with a weft having a circular cross-section, the area A of the contact portion projected in the canvas thickness direction is smaller in the latter case than in the former case, and Since the rate of change in the size of the area A of the contact portion related to the magnitude of the contact force P is greater in the latter case than in the former case, a unit based on the contact force P and the area A of the contact portion. The contact pressure P per area is
In the case of a warp with an elliptical cross-section, the warp becomes larger, and the warp can be deeper crossed at the crossing part with the weft,
The thickness of the canvas can be reduced.

In the present invention, the warp has a thickness dimension × width dimension of 0.25 mm to 0.35 mm × 0.40 mm to 0.70.
A polyester monofilament having a "cross-sectional shape having no linear portion in the thickness direction" in the range of the cross-sectional area inscribed in a circumscribed quadrangle in the range of mm is used, and the weft has a diameter of 0.40.
mm-0.80 mm cross-section circular polyester monofilament is used, the warp filling rate is 125% -175%
Range, weft density is 12 yarns × 2 layers / 2.54 cm to 39
Based on the results of various trial manufacture of dryer canvas with a weft double twill weave structure in the range of 2 × 2.5 / 4 cm, a canvas with a thickness in the range of 1.30 mm to 1.80 mm was found. It was confirmed that it was obtained.

In the warp, the thickness dimension × width dimension is 0.2.
5 mm to 0.35 mm x 0.40 mm to 0.70 mm, in which a polyester monofilament having a "cross-sectional shape without a straight line portion in the thickness direction" in the range of the cross-sectional area inscribed in a circumscribed quadrangle is used, the weft has a diameter of Dimension is from 0.60 mm
Using a circular cross-section polyester monofilament in the range of 1.00 mm, the warp filling rate is in the range of 125% to 175%, and the weft density is 12 threads / 2.54 cm to 35.0 threads /
Based on the results of various trial manufacture of dryer canvas with a weft single-fold twill weave structure in the range of 2.54 cm, it was confirmed that a canvas with a thickness dimension within the range of 1.00 mm to 1.60 mm was obtained. did.

Therefore, according to the present invention, it has a good surface smoothness which can be suitably used in applications requiring a high quality level, such as high-quality paper and paper for coating base paper, and It is possible to realize a dryer canvas for a papermaking machine that has both flexibility in the warp direction and rigidity in the weft direction.

Further, the thickness is 1.80 mm or less, which is applicable to a dry run of a single run canvas system or a type in which cylinders are arranged in a single row, and, for example, a canvas width dimension is 9 m or more and a machine speed max1. It is possible to realize a dryer canvas for a papermaking machine, which is applicable to a wide and high speed paper machine of 500 m / min. Or more and has excellent shape retention characteristics, running stability, and a wide air permeability adjustment range.

The test methods for carrying out the present invention are as follows. Dry heat shrinkage rate Five samples obtained by cutting the raw yarn into a length of 300 mm are treated in a hot air dryer for 20 minutes. The sample taken out is left to stand in a room in a standard state (temperature 20 ° C., relative humidity 65%) for about 30 minutes or more, and then its length is measured, which is represented by the average value of the five samples obtained by the following formula. Dry heat shrinkage (%) = {(300 (mm) -length after treatment (mm)
) / 300 (mm)} × 100 (%)

Air permeability JIS L-1096: 1999 Using a measuring device based on the Frazier method used for measuring air permeability in the "general woven fabric test method", a specified pressure is applied through an air hole having a specified measurement area ( The amount of air that has passed through the test piece per unit time (1 minute) under 125 Pa), that is, the air permeability (cm ³ / cm ² · min) is measured.

Three-Point Bending Rigidity By means of the device shown in FIG. 3, the rollers 42, 43 each having a diameter of 20 mm are fixedly arranged with the both ends of the sample 42 having a width of 3 cm (dimensions in the front and back direction of the paper surface of FIG. 3) spaced 100 mm apart. Stop and place the center of the sample 42 on a round bar 4 with a diameter of 10 mm.
4 and pull upward through a load cell (not shown). Round bar 4
Although the display value of the load cell increases with the pulling amount of 4,
The display value of the load cell will not increase if it is raised to some extent.
The maximum load at this time is called a rigidity value and is expressed in the unit of cN / 3 cm.

When measuring the three-point bending rigidity in the warp direction, the longitudinal direction of the sample 42 (the direction perpendicular to the width dimension of 3 cm) is in the warp direction, and when the three-point bending rigidity in the weft direction is measured, The longitudinal direction is the weft direction.

Deviation Angle FIGS. 4 (B) and 4 (C) show a deviation angle measuring device 50 in which one end of each of the lateral arms 55 and 56 is attached to the upper end portion and the proximal end portion of the fixed support column 54 by a pivot pin 59. It is attached so as to be vertically swingable, and the other ends of the horizontal arms 55 and 56 are linked by a linking arm 57, and the upper horizontal arm 55 is normally fixed to a fixed horizontal arm 60 by a pin 61. Also,
A pointer 58 is attached to the base of the lateral arm 55 on the upper end side to instruct its inclination angle.

Horizontal arm 55 and fixed horizontal arm 60
Then, the upper end of the sample S having a predetermined length and a predetermined width is fixed, and a load W of 1 kg per 1 cm of the width of the sample S is suspended at the lower end. In this state, the lower end of the sample S is fixed to the lower lateral arm 56, and then the load W is removed. In this way, FIG.
The sample S is fixed as shown in FIG.
Apply a downward moment as shown in (C). After leaving in this state for a certain period of time, the deviation dimension x1 (before heating) in FIG.
Heat treatment is performed at 0 ° C. for a certain period of time. After that, the deviation dimension x2 (after heating) is measured again by the pointer 58.

Deviation angles θ1 (before heating), θ2 (after heating)
4A, as shown in FIG. 4A, the displacement dimension x (mm) obtained from the reading of the scale at the position where the pointer 58 fixed to the lateral arm 55 crosses the pointer from the center point of the pivot pin 59. 5
The length up to the tip of 8 is calculated from L (= 120 mm) by the following formula.

Tan θ = x / 120, θ = tan−1 (x / 120) From the deviation angle θ obtained as described above, the deviation of the weave structure during running of the dryer canvas is estimated, and the shape retention characteristics and running of the dryer canvas are estimated. Used for stability evaluation.

Static Friction Coefficient and Dynamic Friction Coefficient FIG. 5 shows a friction coefficient measuring device 30. That is, when the weight S is vertically applied to the sample S by the weight 32 on the contact member 31 fixed as shown in FIG. 5, the wire 33 and the pulley 34 are made to travel in the arrow direction (speed: 50 mm).
/ Min), the static friction force F1 at the start of movement and the dynamic friction force F2 for moving after the start of movement are measured, and the static friction force F
Based on 1 and the dynamic friction force F2 and the load (W = 5 kg), the static friction coefficient μ1 and the dynamic friction coefficient μ2 were calculated from the relational expression of friction coefficient (μ) = friction force (F) / load (W).

As the sample S, a sample having a width dimension of 10 cm and a length dimension of 15 cm is used. When the friction coefficient in the warp direction is determined, the length direction of the sample is the warp direction, and when the friction coefficient in the weft direction is determined, the sample S is used. The length direction of is the weft direction. The direction in which the sample S runs is the length direction of the sample.

(Examples) Next, examples of the present invention and comparative examples to the examples will be described based on Tables 1 to 6. In each table, “TM” represents a polyester monofilament, “PS” represents a paper contact surface side, “BS” represents a non-contact paper surface side, and “high shrinkage yarn” represents a monofilament having a high dry heat shrinkage ratio. The "cross section of the present invention" represents the cross sectional shape of the "filament having no linear portion in the thickness direction" of the present invention, and the "cross sectional area ratio" represents the cross sectional area ratio with respect to the regular elliptical cross sectional area.

[0065]

[Table 1]

(Embodiment 1) The dryer camber of Embodiment 1
100 was manufactured based on the specifications shown in Table 1. sand
That is, the warp yarn 101 has a cross-sectional dimension of 0.30 mm in thickness and width.
One inscribed in a 0.46 mm square with a continuous outline
A cross section of a regular ellipse consisting of curves and defined mathematically
"Thickness direction" with a sectional area ratio of 0.86 to
Cross-sectional shape with no straight portion in the direction "Monofilament {Fig. 2
(B) Cross-sectional shape 21}, the weft 102 has a diameter of 0.
70mm circular polyester monofilament is used
I, 2/2 tear on the paper contact side, weft double weave design with oblique lines {Fig. 7
Using the weave design shown in (A)}, the warp filling rate is 135.1
%, Weft density 16.8 threads × double / 2.54 cm
It was The manufactured dryer canvas has a thickness of 1.79.
mm, air permeability 12,460 cm ³/ cm²・ It was a minute.

Example 2 A dryer canvas 110 of Example 2 was manufactured according to the specifications shown in Table 1. That is, using the same warp 101, weft 102 and weave design as in Example 1, the warp filling ratio was 141.5% and the weft density was 1
It was made into 6.1 pieces × double / 2.54 cm. The manufactured dryer canvas had a thickness of 1.77 mm and an air permeability of 8,950 cm ³ / cm ² · min.

(Example 3) A dryer canvas 120 of Example 3 was manufactured according to the specifications shown in Table 1. That is, using the same warp 101, weft 102, and weave design as in Example 1, the warp filling ratio was 141.8%, and the weft density was 1
It was produced in 7.6 pieces × double / 2.54 cm. The produced dryer canvas had a thickness of 1.70 mm and an air permeability of 4,420 cm ³ / cm ² · min.

In Examples 1 to 3, the monofilament having a high dry heat shrinkage was not used for the weft, but the dry heat shrinkage was lower (3.8% at 160 ° C., 7% at 180 ° C.). The polyester monofilament was used, but since the "cross-sectional shape with no straight line portion in the thickness direction" monofilament was used for the warp, the warp filling rate can be 135.1% to 141.8%, and the width direction of the canvas can be increased. The surface smoothness was good. In addition, since the weave design of the 2/2 torn oblique weft double woven fabric in which the warp floats long on the paper-contacting surface side is used, the surface smoothness in the canvas flow direction is good and the contact area with the wet paper is increased. I was able to do it.

[0070]

[Table 2]

Example 4 The dryer canvas 130 of Example 4 was manufactured according to the specifications shown in Table 2. That is, using the same warp 101 and woven design as in Example 1,
For the weft 102, a polyester monofilament having a circular cross section with a diameter of 0.70 mm and a high dry heat shrinkage rate is used.
Warp filling rate 152.7%, weft density 17.4 yarns × 2 layers /
I made it to 2.54 cm. The manufactured dryer canvas has a thickness of 1.73 mm and an air permeability of 4,300 cm ³ / cm ^2.
・ It was a minute.

(Example 5) A dryer canvas 140 of Example 5 was manufactured in accordance with the specifications shown in Table 2. That is, using the same warp 101 and woven design as in Example 1,
The weft 102 has a diameter of 0.70 mm as in Example 4.
Using a polyester monofilament with a circular dry cross-section and a high dry heat shrinkage, the warp filling rate is 153.5% and the weft density is 2
It was made into 2.0 pieces × double / 2.54 cm. The manufactured dryer canvas had a thickness of 1.75 mm and an air permeability of 1,495 cm ³ / cm ² · min.

(Example 6) A dryer canvas 150 of Example 6 was manufactured according to the specifications shown in Table 2. That is, the warp 101 is inscribed in a quadrangle having a cross-sectional size of 0.25 mm in thickness and 0.50 mm in width, and the outer shape is composed of a single curve, which is a cross section for a regular elliptical cross-sectional area defined mathematically. "Cross-sectional shape without straight portions in the thickness direction" monofilament having an area ratio of 0.86 {Fig. 2
(B) Cross-sectional shape 21}, the weft 102 has a diameter of 0.
Using a polyester monofilament having a circular cross section of 60 mm and a high dry heat shrinkage ratio, a weft double weave design in which the paper contact side is 2/2 torn and oblique (the weave design shown in FIG. 7A) is used, and the warp filling rate is 155. 0.0%, weft density 25.5 yarns × 2 layers / 2.
I made it to 54 cm. The produced dryer canvas is
The thickness was 1.53 mm and the air permeability was 1,395 cm ³ / cm ² · min.

[0074]

[Table 3]

(Example 7) A dryer canvas 160 of Example 7 was manufactured according to the specifications shown in Table 3. That is, the warp 161 is inscribed in a quadrangle having a cross-sectional dimension of 0.35 mm in thickness and 0.46 mm in width, and has a continuous outer shape, which is a curve for a cross section of a regular ellipse defined mathematically. "Cross-sectional shape without straight portions in the thickness direction" monofilament having an area ratio of 0.81 cross-sectional area {Fig. 2
(B) cross-sectional shape 21}, the weft 162 has a diameter of 0.
Using a polyester monofilament having a circular cross section of 70 mm and a high dry heat shrinkage, and using a weft double weave design with a ⅓ tear on the paper contact side (weave design shown in FIG. 7 (B)), the warp filling rate 155 0.6%, weft density 15.8 yarns × 2 layers / 2.
I made it to 54 cm. The produced dryer canvas is
The thickness was 1.77 mm and the air permeability was 9,968 cm ³ / cm ² · min.

Example 8 The dryer canvas 170 of Example 8 was manufactured according to the specifications shown in Table 3. That is, the warp 161 is inscribed in a quadrangle having a cross-sectional dimension of 0.35 mm in thickness and 0.46 mm in width, and has a continuous outer shape, which is a curve for a cross section of a regular ellipse defined mathematically. "Cross-sectional shape without straight portions in the thickness direction" monofilament having a cross-sectional area with an area ratio of 0.89 {Fig. 2
(B) Cross-sectional shape 21}, and using the same weft 162 and woven design as in Example 7, the warp filling ratio 158.1
%, Weft density was 16.3 yarns × 2 layers / 2.54 cm. The manufactured dryer canvas has a thickness of 1.79.
mm, air permeability was 8,110 cm ³ / cm ² · min.

In Examples 4 to 8, monofilaments having a "cross-sectional shape with no straight line portion in the thickness direction" were used for the warp, and the wefts had a dry heat shrinkage of 160% at 12.1% and 180%.
Since a monofilament having a high dry heat shrinkage rate of 19.0% at ℃ was used, the warp filling rate was 152.7% to 158.1%.
And the surface smoothness in the canvas width direction was better than in Examples 1 to 3. In addition, Example 4
In Nos. 6 to 6, since the weave design of the 2/2 torn twill weft double weave in which the warp floats long on the paper contact side was used, the surface smoothness in the canvas flow direction was also good, and the contact area with the wet paper was increased. I was able to increase.

Further, in Examples 1 to 8, the air permeability of the double weft twill weave structure was 1,395 cm due to the above constitution.
It was confirmed that a wide air permeability adjustment range including a low air permeability in the range of ³ / cm ² · min to 12,460 cm ³ / cm ² · min was obtained.

Example 9 The dryer canvas 180 of Example 9 was manufactured according to the specifications shown in Table 3. That is, the same warp as in Example 1 was used as the warp 181 and the weft 1
82 is a polyester monofilament having a circular cross section with a diameter of 0.80 mm and a high dry heat shrinkage ratio, and the warp floats long on the paper-contacting surface side. 2/2 tear Weft 1 double weave design (Fig. 8 (A)) The weaving design shown in FIG.
6%, weft density was 15.5 yarns / 2.54 cm.
The manufactured dryer canvas has a thickness of 1.33 m.
The air permeability was 6,030 cm ³ / cm ² · min.

[0080]

[Table 4]

(Example 10) A dryer canvas 190 of Example 10 was manufactured in accordance with the specifications shown in Table 4.
That is, the same warp and weft as in Example 9 were used for the warp 191 and the weft 192, and the weft 1 double weave design of the 3/1 torn diagonal pattern in which the warp floated for a long time on the paper contact surface side {weave design shown in FIG. 8 (B) }, Warp filling rate 139.5%, weft density 1
It was made into 5.7 pieces / 2.54 cm. The produced dryer canvas has a thickness of 1.30 mm and an air permeability of 5,88.
It was 5 cm ³ / cm ² · min.

In Examples 9 to 10, a monofilament having a "cross-sectional shape with no straight line portion in the thickness direction" was used for the warp, and a dry heat shrinkage ratio (12.1% at 160 ° C, 180% at 180 ° C) was used for the weft.
Since a monofilament having a high dry heat shrinkage of 19.0% at 0 ° C.) was used, the warp filling rate could be increased, and the surface smoothness in the canvas width direction became better. Also,
Since the weave design of 2/2 or 3/1 torn warp weft 1 double woven fabric in which the warp floats for a long time on the paper contact side is used, the surface smoothness in the canvas flow direction is also good, and the contact area to the wet paper is I was able to increase.

[0083]

[Table 5]

(Comparative Example 1) The dryer canvas 300 of Comparative Example 1 was manufactured based on the specifications shown in Table 5. That is, a polyester monofilament having a circular cross section with a diameter of 0.40 mm is used for the warp 101, a circular polyester monofilament with a cross section having a diameter of 0.60 mm is used for the weft 102, and the weft double weave design with a 2/2 tear on the paper contact side is Using the weave design shown in FIG. 7 (A), the warp filling ratio 13
It was manufactured to have a weft density of 1.3% × 17.4 yarns × 2 layers / 2.54 cm. The manufactured dryer canvas had a thickness of 1.89 mm and an air permeability of 15,612 cm ³ / cm ² · min.

(Comparative Example 2) The dryer canvas 310 of Comparative Example 2 was manufactured in accordance with the specifications shown in Table 5. That is, the warp 101 has a circular cross-section polyester monofilament having a diameter of 0.30 mm, the weft 102 has a diameter of 0.60 mm, and the dry heat shrinkage is 12.1% at 160 ° C.
Using a cross-section circular polyester monofilament having a high dry heat shrinkage rate of 19.0% at 180 ° C., a weft double weave design with a 2/2 tear on the paper contact side was used (the weave design shown in FIG. 7A). , Warp filling rate 148.2%, weft density 18.3 yarns ×
It was made double / 2.54 cm. The produced dryer canvas has a thickness of 1.59 mm and an air permeability of 9,114 cm.
^{It was 3} / cm ² · min.

The dryer canvas of Comparative Example 2 has a good surface smoothness that has been used in the drying section of a paper machine for applications requiring high quality level such as high-quality paper and base paper for coating. Is a dryer canvas.

(Comparative Example 3) A dryer canvas 320 of Comparative Example 3 was manufactured based on the specifications shown in Table 5. That is, the warp 101 has dimensions of 0.30 mm in thickness and 0.5 in width.
5 mm square cross-section polyester monofilament, weft 102 has a diameter of 0.80 mm and a dry heat shrinkage of 16
Using a polyester monofilament having a cross section of 12.1% at 0 ° C and 19.0% at 180 ° C with a high dry heat shrinkage,
The weft side of the paper contact side is 2/2 torn and the weave double weave design {Fig. 7 (A)
Was used to produce a warp filling rate of 115.4% and a weft density of 14.0 yarns × 2 layers / 2.54 cm. The manufactured dryer canvas has a thickness of 2.06 mm,
The air permeability was 11,310 cm ³ / cm ² · min.

[0088]

[Table 6]

(Comparative Example 4) A dryer canvas 330 of Comparative Example 4 was manufactured based on the specifications shown in Table 6. That is, the warp 101 has dimensions of 0.30 mm in thickness and 0.5 in width.
5 mm cross-section rectangular polyester monofilament, weft 102 has a diameter of 0.70 mm and a dry heat shrinkage of 16
Using a polyester monofilament having a cross section of 12.1% at 0 ° C and 19.0% at 180 ° C with a high dry heat shrinkage,
The weft side of the paper contact side is 2/2 torn and the weave double weave design {Fig. 7 (A)
Were used to produce a warp filling rate of 119.9% and a weft density of 16.9 yarns × 2 layers / 2.54 cm. The manufactured dryer canvas has a thickness of 1.76 mm,
The air permeability was 4,550 cm ³ / cm ² · min.

The dryer canvases of Comparative Example 3 and Comparative Example 4 have been used in a wide and high-speed paper machine drying section with a canvas width of 9 m or more and a papermaking speed of 1,500 m / min or more. Abundant dryer canvas. (Confirmation of rigidity in flow direction and width direction) Example 1 described above
-10 and the dryer canvases of Comparative Examples 1 to 4 were checked for rigidity in the canvas flow direction (warp direction) and the canvas width direction (weft direction) by the three-point bending rigidity test method shown in FIG.

The number of samples is 3 for each canvas.
The measurement results are shown in Table 7.

[0092]

[Table 7]

In each table, PS (or BS) having three-point bending rigidity means PS (or B) when the direction in which the sample is weighted and pulled up is PS (or BS).
S). Therefore, the state of pressing the wet paper on the cylinder when using the canvas corresponds to the case of pulling up by applying a weight in the BS direction.

The measurement result of the three-point bending rigidity in the warp direction is 88cN / 3c in Example 1 when the load direction is PS.
m, Example 2 with 82 cN / 3 cm, Example 3 with 87 cN
/ 3 cm, 100 cN / 3 cm in Example 4, 110 cN / 3 cm in Example 5, 54 cN / 3 cm in Example 6, 88 cN / 3 cm in Example 7, 92 cN / 3c in Example 8.
m, 95 cN / 3 cm in Example 9, 97 c in Example 10
It was N / 3 cm. On the other hand, in Comparative Example 1, 150 cN /
3 cm, 99 cN / 3 cm in Comparative Example 2, 101 cN / 3 cm in Comparative Example 3, 109 cN / 3 cm in Comparative Example 4.
Met.

When the load direction is BS, 82 cN / 3 cm in Example 1 and 75 cN / 3 cm in Example 2,
83 cN / 3 cm in Example 3 and 95 cN / 3 in Example 4.
cm, 108 cN / 3 cm in Example 5, 53 in Example 6
cN / 3 cm, 88 cN / 3 cm in Example 7, Example 8
Was 92 cN / 3 cm, Example 9 was 95 cN / 3 cm, and Example 10 was 97 cN / 3 cm. On the other hand, Comparative Example 1
Is 117 cN / 3 cm, and Comparative Example 2 is 76 cN / 3 c.
m, 85 cN / 3 cm in Comparative Example 3, 96 in Comparative Example 4
It was cN / 3 cm.

Therefore, the three-point bending rigidity in the warp direction is
Weft double weave texture 110 cN / 3cm or less, weft 1
The heavy twill weave design was 100 cN / 3 cm or less, and it was confirmed that the flexibility in the warp direction was good.

Further, the dryer canvas of the present invention,
The weave design is a double weave design with the same weft, and the polyester monofilament of the same material with the same value in the canvas thickness direction is used for the warp, and the air permeability and the warp filling rate are almost the same or smaller. When comparing with a conventional dryer canvas that has, that is, when comparing Example 2 and Comparative Example 2, Example 1 and Comparative Example 3, or Example 3 and Example 4 and Comparative Example 4, the Example is It was found that the three-point bending rigidity in the warp direction was smaller than that in the comparative example, and the flexibility in the warp direction was extremely good.

Next, the measurement result of the three-point bending rigidity in the weft direction is 935 cN in Example 1 when the load direction is PS.
/ 3 cm, Example 2 is 880 cN / 3 cm, Example 3 is 969 cN / 3 cm, and Example 4 is 1,076 cN / 3 c.
m, 1,291 cN / 3 cm in Example 5, 5 in Example 6
05 cN / 3 cm, Example 7 is 857 cN / 3 cm, Example 8 is 884 cN / 3 cm, and Example 9 is 602 cN / 3.
3 cm, and in Example 10, it was 609 cN / 3 cm. On the other hand, in Comparative Example 1, 627 cN / 3 cm, and in Comparative Example 2, 6
62 cN / 3 cm, in Comparative Example 3 889 cN / 3 cm,
In Comparative Example 4, it was 862 cN / 3 cm.

When the load direction is BS, the first embodiment is 929 cN / 3 cm, and the second embodiment is 881 cN / 3c.
m, 975 cN / 3 cm in Example 3, 1.0 in Example 4
74cN / 3cm, 1,289cN / 3c in Example 5
m, 504 cN / 3 cm in Example 6, 856 in Example 7
cN / 3 cm, Example 8 was 885 cN / 3 cm, Example 9 was 602 cN / 3 cm, and Example 10 was 609 cN / 3.
It was cm. On the other hand, in Comparative Example 1, 665 cN / 3c
m, 668 cN / 3 cm in Comparative Example 2, 9 in Comparative Example 3
It was 31 cN / 3 cm, and in Comparative Example 4, it was 903 cN / 3 cm.

Therefore, the three-point bending rigidity in the weft direction is
500 cN / 3 cm or more in a double weft weave design, weft 1
The heavy twill weave design was 500 cN / 3 cm or more, and it was confirmed that the rigidity in the weft direction was high.

Furthermore, the dryer canvas of the present invention,
Comparison was made with a conventional dryer canvas, which has a weave double weave design with the same weft, and uses polyester monofilament of the same material with the same dimension in the thickness direction of the canvas as the warp and has substantially the same air permeability. In the case, that is, when Example 2 was compared with Comparative Example 2, Example 1 was compared with Comparative Example 3, or Example 3 and Example 4 were compared with Comparative Example 4, the Example was 3 more in the weft direction than the Comparative Example. Large point bending rigidity,
It was found that the three-point bending rigidity in the weft direction was high. (Evaluation of running stability) The deviation angles (θ1, θ2) of the dryer canvases of Examples 1 to 10 and Comparative Examples 1 to 4 before and after heating were measured by the above-described deviation angle test method, The deviation of the weave design during canvas running was estimated, and the morphological stability characteristics and running stability were evaluated.

The number of samples is 3 for each canvas.
The measurement results are shown in Table 8.

[0103]

[Table 8]

As a result, the dryer canvas of the present invention and the polyester monofilament made of the same material are used for the warp, and the circular cross-section polyester monofilament made of the same material having a high dry heat shrinkage is used for the weft, and have substantially the same air permeability. When compared with a conventional dryer canvas having a double weft weave design, that is, Example 7
When comparing Example 8 and Comparative Example 2, the deviation angle (θ1) before heating is 1.2 ° in Example 7, 1.1 ° in Example 8, and 1.0 ° in Comparative Example 2. The deviation angle (θ2) after heating was 2.5 ° in Example 7 and 2.4 in Example 8.
And 2.6 ° in Comparative Example 2, and the misalignment angles before and after heating of the Example were almost the same as those of the Comparative Example.

Further, the dryer canvas of the present invention is a double weave twill weave design having the same weave design, the polyester monofilament of the same material having the same dimension in the thickness direction of the canvas as the warp, and the same cross section. When a circular cross-section polyester monofilament having the same shape and a high dry heat shrinkage rate is used for the weft and a comparison is made with a conventional dryer canvas having substantially the same air permeability, that is, Example 4
In comparison between Comparative Example 4 and Comparative Example 4, the deviation angle (θ
1) was 1.0 ° in Example 4, 1.0 ° in Comparative Example 4, and the deviation angle (θ2) after heating was 2.4 ° in Example 4 and 2.5 ° in Comparative Example 4. Thus, the deviation angles before and after heating of the example were almost the same as or smaller than those of the comparative example.

Therefore, the dryer canvas of the present invention, in particular, has a rectangular cross-section monofilament for the warp, as compared with the dryer canvas (comparative example 2) which has almost the same degree of air permeability and has a long history of use. Compared to the dryer canvas (Comparative Example 4), which has the same woven structure and has almost the same degree of air permeability, and which has a long history of use in the wide and high-speed paper machine drying section (comparative example 4), the deviation of the woven structure during running Were almost the same and were found to have excellent morphological stability characteristics and running stability. (Evaluation of Surface Smoothness in Flow Direction and Width Direction) The static friction coefficient and the dynamic friction coefficient in the flow direction (warp direction) and the width direction (weft direction) of the dryer canvases of Examples 1 to 6 and Comparative Examples 1 to 4 were measured. The surface smoothness in the flow direction and the width direction was evaluated by measuring by the above-mentioned test method.

The number of samples is 3 for each canvas.
The measurement results are shown in Table 9.

[0108]

[Table 9]

As a result, the dryer canvas of the present invention, a weft double twill weave design having the same weave design, a polyester monofilament warp of the same material with the same dimension in the canvas thickness direction, and the same cross-sectional shape In the case of using a circular cross-section polyester monofilament weft made of the same material as above and comparing with a conventional dryer canvas having substantially the same air permeability, that is, Example 1 and Comparative Example 3, or Example 3 and Comparative Example 4. In comparison, the static friction coefficient in the warp direction was 0.177 in Example 1, 0.170 in Example 3, 0.201 in Comparative Example 3, and 0.2 in Comparative Example 4.
The coefficient of kinetic friction in the warp direction is 0.
257, 0.278 in Example 3 and 0.29 in Comparative Example 3.
Comparative Example 4 was 0.285, and the coefficient of static friction in the weft direction was 0.177 in Example 1 and 0.1 in Example 3.
80, Comparative Example 3 was 0.207, Comparative Example 4 was 0.200, and the dynamic friction coefficient in the weft direction was 0.28 in Example 1.
5, 0.248 in Example 3, 0.319 in Comparative Example 3, and 0.311 in Comparative Example 4, and the static friction coefficient in the canvas flow direction (warp direction) and the canvas width direction (weft direction). As for both the coefficient of dynamic friction and the coefficient of kinetic friction, the results were very good in the example compared with the comparative example.

The dryer canvas of the present invention has the same weft double weave weave design, the polyester monofilament warp of the same material having the same value in the thickness direction of the canvas, and the same cross-sectional shape. When using a circular cross-section polyester monofilament weft of the same material having a high dry heat shrinkage and comparing with a conventional dryer canvas having substantially the same air permeability, that is, Example 2 and Comparative Example 2 or Example 4. When compared with Comparative Example 4,
The static friction coefficient in the warp direction was 0.175 in Example 2, 0.165 in Example 4, 0.203 in Comparative Example 2, 0.200 in Comparative Example 4, and the dynamic friction coefficient in the warp direction was in Example 2. 0.
282, 0.254 in Example 4 and 0.29 in Comparative Example 2.
4 and 0.285 in Comparative Example 4, the coefficient of static friction in the weft direction is
0.176 in Example 2, 0.173 in Example 4, 0.214 in Comparative Example 2, 0.200 in Comparative Example 4, and the dynamic friction coefficient in the weft direction was 0.268 in Example 2 and Example 4 0.2
47, 0.275 in Comparative Example 2 and 0.311 in Comparative Example 4, both the static friction coefficient and the dynamic friction coefficient in the canvas flow direction (warp direction) and the canvas width direction (weft direction) The result was very good as compared with the comparative example.

Therefore, the dryer canvas of the present invention has a substantially equal degree of air permeability, and has a surface smoothness superior to that of the conventional canvas (comparative examples 3 and 4) in which square polyester cross-filament filaments are arranged in the warp. In addition, a conventional canvas (Comparative Example 2) having approximately the same air permeability and having a high density of circular cross-section polyester monofilaments with a thin wire diameter arranged in the warp, which is suitable for applications requiring a high quality level. In comparison, it was confirmed that the canvas had excellent surface smoothness in both the flow direction and the width direction.

[0112]

EFFECTS OF THE INVENTION According to the present invention, in a dryer canvas for a papermaking machine made of a synthetic fiber woven fabric, the warp is inscribed in a quadrangle having a thickness smaller than the width and a continuous curve, or a straight line and a continuous curve. A monofilament having a "cross-sectional shape having no straight portion in the thickness direction" having a cross-sectional shape having no straight portion in the thickness direction and having a cross-sectional area larger than the area of a regular ellipse inscribed in the quadrangle Since the warp filling rate is set to a high range of 100% to 175%, the filling rate of the warp is further increased to 130% by using the monofilament having a high dry heat shrinkage rate in at least one weft constituting the woven fabric. Since it is set within the range of ~ 175%, it has excellent surface smoothness compared to the conventional dryer canvas which has a track record of use in applications requiring high quality standards. It is possible to realize a papermaking machine drier canvas which can be suitably used in applications where high quality standards, such as the paper of fine paper and coating base paper is required.

Further, according to the present invention, it is possible to achieve a thickness applicable to a drying section of a single run canvas system or a type in which cylinders are arranged in a single row, and at the same time, a wide width
Wide and high speed that can be applied to high speed paper machines Compared with the conventional dryer canvas that has a proven track record in the drying section of paper machines, it has extremely good flexibility in the warp direction and sufficient rigidity in the weft direction, and , For example, the canvas width is 9m
As described above, it is possible to realize a dryer canvas for a papermaking machine, which has excellent shape retention characteristics and running stability including a machine speed max of 1,500 m / min or more and a wide air permeability adjustment range.

In addition, by using the above-mentioned "cross-sectional shape having no linear portion in the thickness direction" monofilament for the warp,
It is possible to secure a range in which the strength per warp is at least 79% and 96% or less than the strength of the circumscribed quadrangle made of the same material. Therefore, the boundary between the circumscribed quadrangle and the circumscribed quadrangle is 130% to 175%. By setting the warp filling rate corresponding to the area ratio, it is possible to achieve a warp direction strength equal to or higher than that when a monofilament having a circumscribed quadrangular cross-sectional shape is used for the warp.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing various sections of a weave design of a canvas to which the present invention can be applied, the sections being shown from the warp direction cross section,
(A) shows a large amount of warp on the paper-contacting surface 2 /
2 Regular weave and 2/2 torn weave Weave design of double weave, (B)
Is the warp on the paper contact side and the non-paper contact side floats long 3/3
Regular weave or 3/3 torn italic, 3/3 steep torn or 3/3 sudden torn oblique Weft Weave design of double weave, (C) shows many warp yarns on the paper-contacting surface 2 / 1 regular or 2/1 torn oblique weft 1 double weave weave design, (D) shows a lot of warp on the surface of the paper contact side 3/1 regular or 3/1 torn oblique 3 /
It is a weave design of 1 steep or 3/1 sudden torn and weft 1 double weave.

FIG. 2A is a cross-sectional view of a warp yarn having an elliptical cross-sectional shape,
(B) is a cross-sectional view of an example of a warp having a cross-sectional shape according to the present invention, (C) is a cross-sectional view of a different example of a warp having a cross-sectional shape according to the present invention, and (D) is a cross-sectional shape according to the present invention. It is sectional drawing of the further another example of the warp which has.

FIG. 3 is an explanatory diagram of a three-point bending rigidity test method for a dryer canvas.

FIG. 4A is an explanatory view of a deviation angle measuring method of a dryer canvas, FIG. 4B is a perspective view of the dryer canvas deviation angle measuring device under load, and FIG. 4C is a deviation of the dryer canvas deviation angle measuring device. It is a perspective view at the time of angle measurement.

FIG. 5 is a schematic configuration diagram of a friction coefficient measuring device for a dryer canvas.

FIG. 6 (A) is an explanatory view of an enlarged cross-sectional view of a main part on the paper contact surface side of a canvas using a conventional warp having a quadrangular cross section, and (B) is a canvas using a warp having a cross section of the present invention. FIG. 3 is an explanatory diagram of an enlarged cross section of a main part on the paper contact surface side of FIG.

FIG. 7 is a schematic explanatory view from the cross section in the warp direction of each woven fabric used in Examples and Comparative Examples of the present invention, (A)
Is a weave double weave design with a weave of 2/2 torn on the paper contact side, and (B) is a canvas weave design of weft double weave with 1/3 torn on the paper contact side.

FIG. 8 is a schematic explanatory view from the cross section in the warp direction of each woven design used in the examples of the present invention, in which (A) is a 2/2 tear oblique weft in which the warp on the paper contact side floats for a long time. Canvas weave design of single weave design, (B) the warp yarn on the paper contact side floats long 3 /
1 Tear of tears 1 It is a double weave canvas weave.

[Explanation of symbols]

10, 100, 110, 120, 130, 140, 15
0,160,170,180,190,300,31
0, 320, 330 Dryer canvas 11, 101, 161, 181, 191 Warp 12, 102, 162, 182, 192 Weft 13 Paper contact side 14 Non-contact paper side 20 Mathematically defined elliptical shapes 21, 22 23. A cross-sectional shape that is inscribed in a quadrangle whose thickness dimension is smaller than the width dimension and which is composed of continuous curves and has a cross-sectional area larger than the area of a regular ellipse inscribed in the quadrangle, 23. The thickness dimension is smaller than the width dimension. A cross-sectional shape inscribed in a quadrangle, having no straight line portion in the thickness direction composed of straight lines and continuous curves, and having a cross-sectional area larger than the area of a regular ellipse inscribed in the quadrangle 30 Friction coefficient measuring device 50 Deviation angle Measuring device 70 Warp 71 Canvas surface PS Paper contact surface side BS Non-contact paper surface side X Width dimension Y Thickness dimension Z Length of straight part m, k, l, n Curve p Line

Claims (6)

[Claims] 1. A dryer canvas for a papermaking machine, which comprises a synthetic fiber woven fabric, inscribed in a quadrangle having a thickness smaller than the width of a warp, and a continuous curve or a thickness composed of a straight line and a continuous curve. Using a synthetic fiber monofilament having a cross-sectional shape with no linear portion in the direction and having a cross-sectional area larger than the area of a regular ellipse inscribed in the quadrangle, the warp filling rate is within a range of 100% to 175%. A dryer canvas for papermaking machines that is characterized by 2. The synthetic fiber monofilament used for the warp has a thickness dimension × width dimension of 0.25 mm to 0.40 mm.
2. The dryer canvas for a papermaking machine according to claim 1, wherein the dryer canvas has a cross-sectional shape that is inscribed in a quadrangle within a range of 0.35 mm to 0.80 mm and has no straight portion in the thickness direction. 3. A monofilament used for a warp and having a cross-sectional shape without a straight line portion in the thickness direction is inscribed in a quadrangle having a thickness dimension: width dimension ratio of 1: 1.25 to 1: 2. And a cross-sectional area in the range of more than 0.79 times and less than 0.96 times the cross-sectional area of the inscribed quadrangle, and the dryer canvas for a papermaking machine according to claim 1 or 2. 4. A warp filling ratio of 130 is obtained by using a monofilament having a high dry heat shrinkage ratio in at least one layer of the weft yarn.
% To 175% range.
4. A dryer canvas for a papermaking machine according to any one of 3 to 3. 5. A monofilament having a circular cross section having a weft double twill weave design and having a diameter dimension in the range of 0.40 mm to 0.80 mm in at least the paper contact side weft and / or the non-contact paper side weft. With a thickness of 1.30 mm
It is in the range of -1.80 mm, The dryer canvas for papermaking machines in any one of Claim 1 to 4 characterized by the above-mentioned. 6. A monofilament with a circular cross section having a diameter of 0.60 mm to 1.00 mm, which is composed of a weft single-ply weave in which warps float long at least on the paper-contacting surface. The thickness dimension is 1.00 mm to 1.
It is in the range of 60 mm, The dryer canvas for papermaking machines in any one of Claim 1 to 4 characterized by the above-mentioned.