JP2002155489A - Dryer canvas for paper manufacturing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dryer canvas for paper manufacturing, having such surface smoothness and flexibility in the warp direction and also the rigidity in the weft direction as to be suitable for the front group of the drying unit of a paper machine for the applications demanding high-grade levels such as of woodfree paper and base paper for coating use, and furthermore having a thickness applicable to a drying unit in a single-run canvas system or a system with cylinders arranged in a single-raw fashion and also having such high dimensional stability, traveling stability and wide air permeability control range as to be applicable to wide-width and high-speed paper machines with e.g. a canvas width of >=9 m and maximum paper speed of >=1,500 m/min. SOLUTION: This dryer canvas 10 is made of a synthetic textile fabric, wherein monofilaments each with ellipsoidal cross section are arranged as the warps 11 so that the major axial direction of the cross section becomes the cross direction of the canvas and the warp packing rate falls within 100 to 175%.

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 papermaking machine cloth used in a drying section of a paper machine. In particular, the present invention relates to a papermaking dryer canvas having a surface smoothness suitable for applications requiring a high quality level.

[0002]

2. Description of the Related Art A so-called monofilament canvas in which a synthetic fiber monofilament having a circular cross section is used for a warp and a weft is frequently used as a dryer canvas used in a drying section of a paper machine. This is because the stiffness of the monofilament provides excellent dimensional stability, and the smooth yarn surface allows the fabric to have excellent antifouling properties.
Further, it is possible to obtain a fabric having excellent air permeability by utilizing the fact that the fabric has sufficient strength and absorbs very little water. On the other hand, when an extremely low air permeability is required, it may be difficult to achieve this due to the three-dimensional voids inherent in the monofilament woven structure.

[0003] In general, monofilaments are inferior in flexibility to spun yarns and filament yarns. Therefore, at the intersection of the warp and the weft, a convex portion of the warp, that is, a knuckle portion is formed on the surface of the woven fabric. High quality paper or the like, which requires high surface properties because it comes into pressure contact with the cylinder, may cause a mark defect and become a problem. For this reason, the applicants apply a considerable high pressure to the dryer canvas under heating to make the thick yarn having a circular cross section into a flat cross section and flatten the knuckle portion (Japanese Patent Application No. 58-41992), The solution has been sought by polishing the knuckle part formed by weaving the cross-section yarn (Japanese Utility Model Application Laid-Open No. 57-56798). However, equipment for generating a high pressing force under heating is required or the polishing is performed. There was a problem that dirt such as paper powder and filler easily adhered to the rough surface of the warp surface and was poor in antifouling property.

On the other hand, in the device described in Japanese Utility Model Laid-Open No. 7-38194, the warp has a diameter of 0.28 to 0.32.
mm narrow circular cross section polyester monofilament,
Polyester monofilament slightly larger in diameter than warp or polyester monofilament and polyacryl fiber spun yarn slightly larger in diameter than warp, excellent in antifouling property, quality of paper mark etc. of wet paper A dryer canvas having high surface smoothness without causing defects is disclosed.

[0005]

SUMMARY OF THE INVENTION
The dryer canvas disclosed in Japanese Patent Publication No. 94 has a high surface smoothness by arranging a narrow circular cross section polyester monofilament at a high density on a warp, and has a flexibility in a warp direction and an adhesion to a wet paper. Because of its good quality, it is used in applications requiring high quality standards. The air permeability of the dryer canvas disclosed in the publication is 3,000 c.
m ³ / cm ² · min to 16,000 cm ³ / cm ² · mi
n.

On the other hand, in recent years, the width and speed of a paper machine have become remarkable, and for example, the speed of the paper machine has been increased up to 1500 m / m.
min.
The dryer canvas disclosed in Japanese Patent Laid-Open Publication No. H10-143 is not necessarily perfect in order to ensure stable operation of the paper machine in response to such widening and high speed of the paper machine.

[0007] In general, in applications that require a high quality level, such as papermaking of high quality paper and base paper for coating, not only the quality defect such as a paper mark of the wet paper does not occur but also the wet paper. The demand for uniformity of drying in the flow direction and the width direction is severe. Therefore, it is necessary to bring the wet paper into uniform contact with the cylinder, and it is required for the dryer canvas to maintain uniform adhesion and pressing force with the wet paper in the flow direction and the width direction, even under a wide width and high speed. .
Therefore, it is necessary to have good surface smoothness and flexibility in the warp direction, and also to have both strength in the warp direction and rigidity in the weft direction.

On the other hand, as the structure of the drying section of the multi-cylinder dryer for papermaking, a conventional upper and lower canvas system in a two-stage dryer, a single-run canvas system as an improvement thereof, and a further improvement thereof have been proposed. The bell-run system (trademark of Beloit, USA) and the simran system (trademark of Valmet, Finland), in which cylinders are arranged in a single row, have been proposed, and improvements have been made to prevent sheet fluttering due to an increase in papermaking speed. Has been made. In the single-run canvas system, on the lower cylinder, and in the bell-run system, on the suction roller provided between the cylinders, the wet paper runs on the outer periphery of the dryer canvas, so the upper cylinder part and the lower cylinder part Due to the difference in the peripheral speed corresponding to the thickness of the canvas, the tension and looseness of the wet paper web repeats as the wet paper web travels, adversely affecting the wet paper web and severely cutting the paper Defects such as were sometimes generated. For this reason, it is indispensable that the thickness of the canvas is particularly small in the single-run canvas system, the bell-run system, and the simran system that perform high-speed papermaking.

Therefore, the present invention can be suitably used in applications requiring a high quality level, such as papermaking of high-quality paper and base paper for coating. It is an object of the present invention to provide a papermaking dryer canvas having good surface smoothness and flexibility in the warp direction, which can be particularly preferably used in a front group having a relatively high ratio, and also has rigidity in the weft direction. .

Further, the thickness is applicable to a single-run canvas system or a drying unit of a type in which cylinders are arranged in a single row.
An object of the present invention is to provide a papermaking dryer canvas having excellent dimensional stability and running stability and a wide range of air permeability adjustment, which can be applied to a wide and high speed paper machine of ax 1500 m / min or more.

[0011]

In order to obtain a papermaking dryer canvas having good surface smoothness and flexibility in the warp direction, it is necessary to use a warp as in the invention disclosed in Japanese Utility Model Publication No. 7-38194. In addition to high-density circular monofilaments with a small circular cross section, there are also those using so-called flat monofilaments with a cross section (hereinafter referred to as quadrangular monofilaments) with appropriate thickness and width for the warp. A canvas woven into the tissue is used.

However, it has been found that the following problems also occur in a dryer canvas using a quadrangular monofilament in warp.

That is, in order to achieve a wide air permeability range including a low air permeability while maintaining a high surface smoothness and a small thickness dimension, it is necessary to increase the density of the weft yarns and the warp length floating weave structure. Therefore, it is necessary to set the warp density high, for example, in a high range in which the warp filling ratio exceeds 100%, in which case, it is necessary to cope with such a problem. Each other interferes with each other, making it difficult to secure the desired high range of filling factor.In addition, as the filling factor is increased to a certain extent, the flat surface of the cross-section square monofilament and the parallelism of the canvas surface are maintained It becomes impossible (see FIG. 6 (A)), and in a part of the canvas surface, the quadrangular corner of the warp 70 is exposed on the canvas surface 71, and the surface property is particularly improved in the canvas width direction. Influence comes thing, also, the problem of the things that cause a deterioration such as weaving efficiency affect the handling of the warp at the time of weaving has been found. Applicants have found that, for example, in the case where a cross-section square polyester monofilament having a size of 0.3 mm × 0.55 mm is used for the warp, the warp filling rate is 125%.
Experience has shown that ~ 130% is a practical upper limit.

On the other hand, in order to secure the rigidity in the weft direction while keeping the flexibility and thickness in the warp direction small,
It is necessary to make the canvas thickness direction of the warp relatively small and increase the diameter of the weft, but in this case, the rigidity of the weft increases as compared to the rigidity of the warp, and it is difficult for the weft to crimp. Therefore, it is necessary to further entangle the warp at the entanglement point with the weft.

In view of the above problems, the present invention is characterized by having the following configuration.

That is, the present invention relates to a papermaking dryer canvas comprising a synthetic fiber woven fabric, wherein a monofilament having an elliptical cross section is disposed on a warp so that the major axis direction thereof is in the canvas width direction, and the warp filling factor is used. Is 100% to 1
It is characterized by being within the range of 75%. The warp filling ratio is preferably in the range of 125% to 175%.

Further, the present invention uses a monofilament having a high dry heat shrinkage rate for at least one weft constituting the woven fabric and has a warp filling rate of 130% to 175%, preferably 150% to 175%. It is characterized by being within the range.

In addition, the present invention provides the woven fabric, wherein the woven fabric has a weft double oblique weave structure in which at least the warp on the surface on the side of the paper contact surface is long, and the warp has a minor axis × major axis of 0 mm. .25
characterized in that a monofilament having an elliptical section is used in the range of mm to 0.35 mm x 0.40 mm to 0.70 mm, and the ratio of the minor axis to the major axis is in the range of 1: 1.6 to 1: 2. I do.

Further, according to the present invention, the contact side weft and the non-contact side weft each have a diameter of 0.4 mm to 0.4 mm.
A circular monofilament having a circular section within a range of 8 mm and a weft density of 15 yarns / 2 / 2.54 cm to 48
It is characterized by being within the range of book × 2 / 2.54 cm.

Further, the present invention is characterized in that the warp and the weft are woven using a polyester monofilament, the dimensional reduction ratio in the canvas thickness direction is in the range of 82.0% to 90.0%, and the canvas thickness is reduced. 1.23mm-1.
It is within a range of 8 mm.

In the present invention, the warp and the weft are preferably
Woven using a PS monofilament, the dimension reduction rate in the canvas thickness direction is within a range of 84.0% to 92.0%, and the canvas thickness is 1.26 mm to 1.85 m.
m.

Furthermore, the present invention is a woven fabric, wherein the woven fabric is composed of a single weft oblique weave structure in which at least the warp on the surface on the side of the paper contact surface is long floating, and the warp has a minor axis × major axis of 0. 25m
It is characterized by using a monofilament having an elliptical cross-section having a range of m to 0.35 mm x 0.40 mm to 0.70 mm and a ratio of a minor axis to a major axis within a range of 1: 1.6 to 1: 2. I do.

Further, according to the present invention, each of the wefts is preferably
A monofilament having a circular cross section having a diameter in the range of 0.6 mm to 1 mm, and a weft density of 15 filaments / 2.
It is in the range of 54 cm to 35 lines / 2.54 cm.

Further, the present invention is characterized in that the warp and the weft are woven using a polyester monofilament, the dimensional reduction ratio in the canvas thickness direction is in the range of 90.5% to 95.0%, and the canvas thickness is reduced. 1.0mm to 1.6mm
It is characterized by being within a range of 1 mm.

In the present invention, the warp and the weft are preferably made of P
Woven using a PS monofilament, the dimensional reduction rate in the canvas thickness direction is within a range of 93.6% to 97.0%, and the canvas thickness is 1.03 mm to 1.65 m.
m.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The papermaking dryer canvas of the present invention is a papermaking dryer canvas made of a synthetic fiber fabric, in which a monofilament having an elliptical cross section is arranged in a warp so that the major axis direction is the canvas width direction. Used
The warp filling ratio is in the range of 100% to 175%. This configuration has a warp filling ratio of 125% to 17%.
It is more effective in the range of 5%.

Here, the monofilament having an elliptical cross-section means not only an accurate ellipse 20 whose cross-section is mathematically defined as shown in FIG. Shape, the exact elliptical shape or the substantially elliptical shape as shown in FIG.
2 having a substantially elliptical cross section having a straight portion 23 and FIG.
As shown in FIG. 4C, the cross-sectional shape 24 in which two to four of the four corners are rounded 25 in an arc shape is included.

In the present invention, by using a monofilament having an elliptical cross section as a warp, for example, as shown in FIG. 6 (B), a smooth curved surface shape works effectively. As shown in A), when the warp 70 is a square monofilament having a cross section, there is a problem that the side faces of adjacent monofilaments interfere with each other and it becomes difficult to secure a desired high range of filling rate. In addition, problems such as an adverse effect on the surface quality of the canvas due to the occurrence of the inclination of the monofilament surface with respect to the canvas surface 71 are eliminated.

Further, since a monofilament having an elliptical cross section is used for the warp, the warp can be entangled more deeply at the point of entanglement with the weft than when a monofilament having a rectangular cross section is used. Is improved.

The papermaking dryer canvas of the present invention is a synthetic fiber woven fabric woven using synthetic fiber yarns for the warp and the weft.

Examples of the synthetic fiber yarn include PPS having excellent heat resistance, including polyester fibers such as PET and PBT, polyamide fibers such as nylon 6, nylon 46 and nylon 66, and polyolefin fibers such as polypropylene.
Synthetic fiber yarns mainly composed of PEEK and PEEK are used alone or in combination with the warp and / or weft. Polyester fibers such as PET and PBT are preferable in terms of dimensional stability, wear resistance, bending fatigue resistance and the like, and PPS and PEEK are preferable in terms of heat resistance and the like.

The weaving structure includes single weft, double weft, and 2.
Known weaving structures such as five-ply, three-ply weave, plain weave, satin weave, and the like can be used, but the warp has a long floating structure to improve the flatness of the surface, and can be used in the canvas flow direction, that is, the warp direction. It is preferable that the area of contact with the wet paper is increased, and a double weft or single weft oblique weave design in which at least the warp yarn on the surface on the paper contact side is long-floating is suitable. The weave structure in which the warp is long floating means a structure in which the warp straddles two or more wefts. In the weft double oblique weave structure in which at least the warp on the surface on the side of the contacting surface is long floating, FIG. A) As shown in (B), many warp yarns appear on the surface on the paper contact side.
2 regular oblique sentence or 2/2 torn oblique sentence (Fig. 1 (A)), 3/3 regular oblique sentence or 3/3 broken oblique sentence (Fig. 1 (B)), 3/3 steep oblique sentence or 3/3 A woven structure such as a sharply broken oblique text (FIG. 1B) can be used. Also, as shown in FIGS. 1 (C) and 1 (D), a 2/1 regular oblique sentence or a 2/1 tear oblique sentence (FIG. 1 (C)) in which a large amount of warp appears on the surface of the paper contacting side. 2 /
2 regular oblique sentences, 2/2 broken oblique sentences, 3/1 regular oblique sentences, 3/1
It is possible to use an oblique weave structure having a single weft, such as a torn sentence (FIG. 1 (D)), a 3/1 steeply inclined sentence, or a 3/1 steeply torn inclined sentence (FIG. 1 (D)).

To increase the filling rate of the warp, in addition to the setting of the warp density during weaving, processing conditions that increase the amount of shrinkage in the weft direction during heat setting and a weft with a high dry heat shrinkage are selected. Used. When a weft having a high dry heat shrinkage is used, it is used for at least one layer of the weft. When used for all the weft layers, the filling rate of the warp can be increased. It is preferable to use it for the weft on the paper contact surface side in order to increase the contact area with the wet paper. In the case of using a weft having a high dry heat shrinkage, a filling rate of the warp of 130% to 175%, preferably 150% to 175% can be realized.

In the practice of the present invention, a monofilament having a high dry heat shrinkage ratio used for a weft is one filament at 160 ° C.
2% to 26%, 14% to 30% at 180 ° C, more preferably 12% to 21.4 at 160 ° C.
%, Which has a dry heat shrinkage in the range of 14% to 24% at 180 ° C., and is generally available for dryer canvas. For example, in polyester monofilament, Shakespeare's PX-4
05 is on the market and available.
No. 170034, Japanese Patent Publication No. 9-510748,
JP-A-8-302524, Tokkaihei 4-50024
No. 7 has disclosed. Further, among PPS monofilaments, there are those disclosed in JP-A-5-195318.

In practicing the present invention, the cross-sectional dimension of the cross-sectional elliptical shape of the warp is defined as a minor axis × major axis of 0.25 mm to 0.3 mm.
The ratio of the minor axis to the major axis is in the range of 5 mm × 0.40 mm to 0.70 mm and in the range of 1: 1.6 to 1: 2. 1: 2
The upper limit is set in order to avoid that the number of warps in the canvas width direction decreases and the tension load per warp during weaving and use becomes excessive. Dryer canvases using monofilaments for warp and weft have poor cushioning properties compared to those made of multifilament yarns or spun yarns, so the tension in the warp direction during use is set higher than those canvases, and wet paper In such a case, a gearless drier may be provided in the drying section of the paper machine. In such a case, a tension load max3 kg / c on the canvas is applied.
Although m is used as a reference, in order to ensure stable operation and durability in response to abrasion and thermal deterioration of the warp, it is necessary to reduce the tension load per warp.
On the other hand, in order to effectively exhibit the flatness in the canvas width direction of the monofilament having an elliptical cross section, the lower limit of the ratio of the minor axis to the major axis is 1: 1.6.

As the weft, a monofilament is used at least on the paper contact surface side and / or the non-paper contact surface side. As the cross-sectional shape of the weft, a polygonal shape such as a triangle, a square, a rectangle, a quadrangle, a hexagon, and an octagon other than a circle and an ellipse, and a shape obtained by partially changing these shapes can be used. Other wefts include monofilament yarns and / or multifilament yarns and / or spun yarns composed of aligned or twisted yarns, and covered helical or coiled core-sheath structures. Yarns and the like can be used, but from the viewpoint of preventing adhesion of dirt due to paper dust or filler on the canvas and removing dirt adhering to the canvas, it is preferred that the weft yarn on the paper contact side and the weft on the anti-paper contact surface side be composed of monofilaments.

Preferably, the shape, size and density of the weft are adjusted to be at least two in the case of a double weave texture in which the warp on the surface on the contact side is long floating. Each has a diameter of 0.4mm to 0.8m
m, and the weft density is in the range of 15 × 2 / 2.54 cm to 48 × 2 / 2.54 cm, preferably 15 × 2 / 2.5.
Set within the range of 2.54 cm to 39 lines × 2 / 2.54 cm. More preferably, the diameter is between 0.5 mm and 0.8 mm
, And in that case, the weft density is 15 yarns × 2 /
2.54 cm to 40.6 lines x 2 / 2.54 cm, preferably 15 lines x 2 / 2.54 cm to 33.8 lines x 2 / 2.5
It is set and used within a range of 4 cm.

[0038] Preferably, in the case of a single weft oblique weave structure in which at least the warp on the surface of the paper contact side is long-floating, the weft has a circular cross section having a diameter in the range of 0.6 mm to 1 mm. At the same time as using the monofilament, the weft density is in the range of 15 yarns / 2.54 cm to 35 yarns / 2.54 cm, preferably 15 yarns / 2.54 cm to 30 yarns / 2.54 cm.
cm.

It is a matter of course that the shape, size and density of the weft may be different depending on the weft on the contact side and the weft on the opposite side.

The lower limit of the weft density is a lower limit for satisfying the required surface smoothness, rigidity in the weft direction, running stability, shape retention and the like, and for obtaining the required upper limit of the air permeability range. Further, the upper limit of the weft density is the maximum of the number of wefts that can be arranged in the canvas flow direction under the minimum value of the warp thickness in the thickness direction and the minimum diameter of the weft in the oblique weave design. Obtained from the value. In order to achieve such a high weft density, tension conditions and temperature conditions during weaving and processing are appropriately set so as to increase the amount of shrinkage in the warp direction during heat setting, and for example, warp It is preferable to select and use a monofilament having a high dry heat shrinkage.

In the present invention, the warp filling rate is 100% to 175% by using a monofilament having an elliptical cross section for the warp.
In combination with the above-mentioned setting range of the weft density, it is possible to have good surface smoothness and a wide air permeability range, and at the same time, secure rigidity in the canvas width direction. That is, due to the high warp filling rate and high weft density,
Even lower air permeability than before can be realized. Further, even when a low weft density is taken to obtain a high air permeability range, the surface smoothness can be maintained satisfactorily because the warp filling ratio is high.

The rigidity in the width direction generally increases as the dimension of the weft in the canvas thickness direction increases. However, the present invention uses a monofilament having a cross section of a warp having an elliptical cross section while using a weft diameter in the above range. It is arranged and used so that the major axis direction is the canvas width direction, and the filling rate of the warp is set high so that the warps adjacent to the canvas in the width direction are sufficiently adhered. The effect of reducing the degree of freedom with respect to the bending in the width direction of the canvas is produced, and in combination with the rigidity of the circular monofilament having a circular cross section in the above-mentioned diameter dimension range, the warp has a greater effect than the case of using a circular cross section or a quadrangular cross section monofilament. The rigidity in the width direction can be improved. As a result, it is possible to ensure excellent running stability and shape retention that can meet the applications to which the dryer canvas of the present invention is suitable, particularly, the requirement of a canvas width of 9 m or more.

The present invention relates to a drier canvas woven using polyester monofilaments for the warp and the weft, and in the case of a double weft oblique weave structure in which at least the warp on the surface on the side of the paper contact surface is long floating, the canvas thickness is The dimension reduction rate in the direction is in the range of 82.0% to 90.0%, and the thickness thereof is in the range of 1.23 mm to 1.8 mm. In the case of a single-layer oblique weave structure in which the warp on the side surface floats long, the dimensional reduction rate in the canvas thickness direction is 90.5% to 9%.
Within a range of 5.0% and a thickness of 1.0 mm
It is characterized by being within the range of 1.61 mm.

The present invention also relates to a method for producing PPS for warp and weft.
In a dryer canvas woven using a monofilament, in the case of a weft double oblique weave structure in which at least the warp yarns on the surface on the paper contact side are long-floated, the dimensional reduction rate in the canvas thickness direction is 84.0% to 92%. 2.0%, and the thickness thereof is in the range of 1.26 mm to 1.85 mm. In the case of the oblique weave structure, the dimensional reduction rate in the canvas thickness direction is 93.6% to 9%.
Within a range of 7.0% and a thickness of 1.03 m
m to 1.65 mm.

Accordingly, it is possible to achieve a thickness of 1.8 mm or less (preferably 1.7 mm or less) applicable to a single-run canvas system or a drying unit of a type in which cylinders are arranged in a single row.

The dimension reduction ratio in the thickness direction of the canvas is a percentage expressed as a quotient obtained by dividing the thickness of the manufactured canvas by the total value of the dimensions in the thickness direction of the warp and the weft constituting the canvas fabric. Further, the total value of the canvas thickness direction dimensions of the warp and the weft constituting the woven fabric is the thickness direction dimension of the warp and the thickness of the weft constituting the weft layer, which are exposed on the contact side and the non-contact side. This is the sum of the dimensions in the direction.

The thickness range and the dimensional reduction rate in the thickness direction can be determined by using a monofilament having an elliptical cross section for the warp, and at the same time, the materials and dimensions of the warp and the weft, the dry heat shrinkage,
In addition, processing conditions during weaving and heat setting are appropriately set and realized. Furthermore, it can be realized by using a monofilament having a high dry heat shrinkage rate for the weft. As a result, the warp can be entangled more strongly at the entanglement point with the weft, and the crimp is generated more strongly by the weft, so that the above-mentioned thickness dimension ratio can be satisfied. This makes it difficult for the canvas weave to be misaligned, and is effective in improving running stability, which tends to be insufficient in the case of a weave in which the warp floats long.

Further, the present invention provides a warp having an elliptical cross section in contact with a weft having a circular cross section and a warp having a rectangular cross section in contact with a weft having a circular cross section. Taking advantage of what can be entangled,
The thickness range and the dimensional reduction rate in the thickness direction are realized.

That is, for example, when a contact force P based on a tension T per unit length applied to a weft acts, a warp having a rectangular cross section abuts a weft having a circular cross section, and a warp having an elliptical cross section has a cross section. In the case of abutting on a circular weft, the area A of the abutting portion projected in the canvas thickness direction is smaller in the latter case than in the former case, and also in relation to the magnitude of the abutting force P. Since the rate of change in the size of the area A of the contact portion is larger in the latter case than in the former case, the contact pressure p per unit area based on the contact force P and the area A of the contact portion is In the case of a warp having an elliptical cross-section, the warp becomes larger, the warp can be entangled deeper at the point of entanglement with the weft, and the thickness of the canvas can be reduced.

In the present invention, the warp has a minor axis × major axis of 0.25
mm-0.35 mm × 0.40 mm-0.70 mm in cross-section elliptical polyester monofilament, and weft made of cross-section circular polyester monofilament in diameter of 0.5 mm-0.8 mm, with 100% warp filling factor
~ 175% range, weft density is 15 strands x 2 / 2.54c
Based on the results of various trial manufactures of dryer canvases having a double weave texture with a range of m to 40.6 lines × 2 / 2.54 cm, the dimensional reduction rate in the canvas thickness direction was 82.0.
% To 90.0%, and the thickness is 1.23 mm to
It was confirmed that a canvas within a range of 1.80 mm was obtained.

The warp has a minor axis × major axis of 0.25 mm or more.
An oval polyester monofilament having a cross section in the range of 0.35 mm × 0.40 mm to 0.70 mm and a circular polyester monofilament having a cross section having a diameter of 0.6 mm to 1.0 mm are used for the weft, and the warp filling ratio is 100% to 17%.
In the range of 5%, the weft density is 15 yarns / 2.54 cm to 35.
Based on the results of various trial productions of a dryer canvas having a single weave with a weave of 0 / 2.54 cm, the dimension reduction rate in the canvas thickness direction was 90.5% to 95.0%.
It was confirmed that a canvas having a thickness of 1.0 mm to 1.61 mm was obtained.

In the present invention, the warp has a minor axis × major axis of 0.25
mm-0.35 mm × 0.40 mm-0.70 mm in cross section elliptical PPS monofilament, circular cross section PPS monofilament in diameter in the range 0.5 mm-0.8 mm for weft, warp filling ratio 100%- 175% range, the weft density is 15 strands x 2 / 2.54 cm-40.6
Based on the results of various prototypes of dryer canvases with a weft double weave texture with a range of book x 2 / 2.54 cm,
Dimension reduction rate in the canvas thickness direction is 84.0% to 92.0%
% And the thickness is 1.26 mm to 1.85 mm
It was confirmed that a canvas within the range was obtained.

The warp has a minor axis × major axis of 0.25 mm or more.
PPS monofilament having an elliptical cross section in the range of 0.35 mm x 0.40 mm to 0.70 mm, and the weft has a diameter of 0.6.
mm PPS monofilament having a circular cross section in a range of 1.0 mm to 1.0 mm, and a warp filling ratio in a range of 100% to 175%;
Weft density: 15 yarns / 2.54 cm-35.0 yarns / 2.5
Based on the results of various trial productions of dryer canvases having a single weft texture with a weft width of 4 cm, the dimensional reduction rate in the canvas thickness direction is within the range of 93.6% to 97.0%, and It was confirmed that a canvas having a diameter of 1.03 mm to 1.65 mm was obtained.

With the above configuration, the air permeability is from 1,095 cm ³ / cm ² · min to 14,000 cm ³
/ Cm ² · min, a three-point bending stiffness in the warp direction (a test method will be described later) of 110 cN / 3 cm or less, and a three-point bending stiffness in the weft direction of 500 cN / 3 cm or more can be achieved. In particular, in the air permeability adjustment range, it was difficult to achieve a monofilament canvas in which the warp and the weft were composed of monofilaments.
A low air permeability of 95 cm ³ / cm ² · min can be achieved.

Therefore, according to the present invention, it can be suitably used in applications requiring a high quality level, such as papermaking of high quality paper and base paper for coating. A dryer canvas having good surface smoothness, flexibility in the warp direction, and rigidity in the weft direction, which can be particularly preferably used in the front group having a relatively high moisture content in wet paper, can be realized.

Further, the present invention is applicable to a single-run canvas system or a drying unit in which cylinders are arranged in a single row.
The thickness is 8 mm or less (preferably 1.7 mm or less), and, for example, the canvas width is 9 m or more, and the papermaking speed max15
A papermaking dryer canvas having excellent dimensional stability, running stability, and a wide range of air permeability that can be applied to a wide and high-speed paper machine of 00 m / min or more can be realized.

The method of each test related to the implementation of the present invention is as follows.

Dry Heat Shrinkage Five samples obtained by cutting the original yarn into a length of 300 mm are treated in a hot air drier for 20 minutes. The taken-out sample was left in a room in a standard condition (temperature: 20 ° C., relative humidity: 65%) for about 30 minutes or more, and its length was measured. The length was represented by an average value of five samples obtained by the following equation. Dry heat shrinkage (%) = ｛(300 (mm) -length after treatment
(mm)) / 300 (mm) x 100 (%)

Air permeability According to JIS L-1096: 1999 Frazier method. The amount of air that has passed through the sample under a pressure of 125 Pa is expressed in terms of a unit area per minute.

Three-point bending stiffness The apparatus shown in FIG. 3 is used to lock a sample 42 having a width of 3 cm (dimensions in the front and back sides of FIG. 3) with round rods 43, 43 having a diameter of 20 mm and fixedly arranged with both ends separated by 100 mm. Then, the central portion of the sample 42 is pulled upward via a roller 44 having a diameter of 10 mm and a load meter (not shown). The display value of the load cell increases with the amount of pulling of the roller 44, but when the roller is pulled up to some extent, the display value of the load cell does not increase. The maximum load at this time is called a stiffness value and is expressed in units of cN / 3 cm.

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

4 (B) and 4 (C) show a displacement angle measuring device 50 in which upper ends of fixed columns 54 and one ends of horizontal arms 55 and 56 at a base end are vertically swingably mounted. Horizontal arm 55, 56
The other end is connected by a connecting arm 57, and the upper horizontal arm 55 is always fixed to a fixed horizontal arm 60 by a pin 61.

The upper end of the sample S having a predetermined length and a predetermined width is fixed to the horizontal arm 55, 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 horizontal arm 56, and then the load W is removed. Thus, the sample S is fixed as shown in FIG. 4B, the pin 61 is pulled out, and a downward moment is applied as shown in FIG. 4C. After leaving for a certain period of time in this state,
(Before heating) is measured, and a heat treatment is performed at a temperature of 180 ° C. for a certain time in that state. Thereafter, the dimension x (after heating) of the deviation is measured again.

As shown in FIG. 4A, the displacement angles θ1 (before heating) and θ2 (after heating) are calculated by calculating the displacement dimension x (mm) and the length from the pivot pin 59 to the tip of the pointer 58 as L. (= 12
0 mm) is calculated by the following equation.

Tan θ = x / 120, θ = tan
-1 (x / 120)

From the deviation angle θ obtained as described above, the deviation of the weaving structure during running on the canvas is estimated and used for evaluating the running stability of the canvas.

Coefficient of static friction and coefficient of kinetic friction As shown in FIG. 5, when the sample 32 is run in the direction of the arrow with the load W applied in the vertical direction on the fixed contact member 31 (speed 50 mm / min), it starts to move. Friction force F1
Then, the dynamic friction force F2 for moving after starting to move is measured (for example, a spring scale is installed in the middle of a drawstring and its value is checked), and the static friction force F1, the dynamic friction force F2 and the load (W = 5k)
g), a static friction coefficient μ1 and a dynamic friction coefficient μ2 were calculated from a relational expression of friction coefficient (μ) = frictional force (F) / load (W).

A sample was 10 cm wide and 15 cm long.
When the friction coefficient in the warp direction is obtained, the length direction of the sample is the warp direction, and when the friction coefficient in the weft direction is obtained, the length direction of the sample is the weft direction. The direction in which the sample 32 runs is the length direction of the sample.

(Examples) Next, Examples of the present invention and Comparative Examples to this Example will be described based on Tables 1 to 6. In each table, TM represents the polyester monofilament, PS represents the paper contact side, and BS represents the non-contact side. High shrink yarns represent monofilaments with high dry heat shrinkage.

(Example 1) The dryer canvas 100 of Example 1 was manufactured based on the specifications shown in Table 1 and the weave structure shown in FIG. That is, the warp 101 has a thickness of 0.
3 mm × 0.46 mm wide cross-sectional elliptical polyester monofilament (cross-sectional shape 20 in FIG. 2A), weft 10
2 is made of a polyester polyester filament having a cross section of 0.7 mm in diameter and having a weft double weave structure of 2/2 tear oblique on the paper contact side and 3/1 tear oblique on the anti-paper side, and a warp filling rate of 135.1. %, Weft density 16.8 threads × 2 / 2.54cm
Made in. The manufactured dryer canvas has a thickness of 1.
79mm, dimension reduction rate in thickness direction 89.5%, air permeability 1
It was 2,779 cm ³ / cm ² · min.

(Example 2) The dryer canvas 110 of Example 2 was manufactured based on the specifications shown in Table 1 and the woven structure shown in FIG. That is, the warp 101 has a thickness of 0.
3 mm × 0.46 mm wide cross-sectional elliptical polyester monofilament (cross-sectional shape 20 in FIG. 2A), weft 10
2 was made of a polyester monofilament having a cross section of 0.7 mm in diameter and having a weft double weave structure with a 2/2 tear oblique on the paper contact side and a 3/1 tear oblique on the anti-paper side, and a warp filling rate of 141.5. %, Weft density 16.1 yarn × 2 / 2.54 cm
Made in. The manufactured dryer canvas has a thickness of 1.
It was 77 mm, the dimension reduction rate in the thickness direction was 88.5%, and the air permeability was 9,145 cm ³ / cm ² · min.

Example 3 The dryer canvas 120 of Example 3 was manufactured based on the specifications shown in Table 1 and the woven structure shown in FIG. That is, the warp 101 has a thickness of 0.
3 mm × 0.46 mm wide cross-sectional elliptical polyester monofilament (cross-sectional shape 20 in FIG. 2A), weft 10
2 is made of a polyester monofilament having a cross section of 0.7 mm in diameter and having a weaving double weave structure with a 2/2 tear oblique on the paper contact side and a 3/1 tear oblique on the anti-paper side, and a warp filling ratio of 141.8. %, Weft density 17.6 threads × 2 / 2.54cm
Made in. The manufactured dryer canvas has a thickness of 1.
70 mm, the dimension reduction rate in the thickness direction was 85.0%, and the air permeability was 4,520 cm ³ / cm ² · min.

In Examples 1 to 3, a monofilament having a high dry heat shrinkage was not used for the weft, but a lower dry heat shrinkage (3.8% at 160 ° C. and 7% at 180 ° C.) was used. Although a polyester monofilament was used, since an elliptic cross-section polyester monofilament was used for the warp, the warp filling rate could be 135.1% to 141.8%, and the surface smoothness in the canvas width direction was improved. Was. In addition, since the paper contact side has a 2/2 tear oblique weft double weave structure in which the warp floats long, the surface smoothness in the canvas flow direction is good, and the contact area with the wet paper can be increased. done.

In Example 3, as a result of setting the tension conditions at the time of processing after weaving to be higher than those in Examples 1 and 2, so that the warp is more entangled with the weft at the entanglement point,
A thickness of 1.70 mm was achieved.

Example 4 The dryer canvas 130 of Example 4 was manufactured based on the specifications shown in Table 2 and the weave structure shown in FIG. That is, the warp 101 has a thickness of 0.
3 mm × 0.46 mm wide cross-sectional elliptical polyester monofilament (cross-sectional shape 20 in FIG. 2A), weft 10
2 is a polyester monofilament having a circular cross section with a diameter of 0.7 mm and a high dry heat shrinkage ratio, and the paper contact side is 2
The weft was prepared with a weaving double weaving structure with a 3/2 tear oblique and a 3/1 tear oblique on the paper surface side, a warp filling rate of 152.7%, and a weft density of 17.4 yarns / 2 / 2.54 cm. The manufactured dryer canvas has a thickness of 1.80 mm and a dimensional reduction rate of 9 in the thickness direction.
The air permeability was 0.08% and the air permeability was 4,887 cm ³ / cm ² · min.

Example 5 The dryer canvas 140 of Example 5 was manufactured based on the specifications shown in Table 2 and the weave structure shown in FIG. That is, the warp 101 has a thickness of 0.
3 mm × 0.46 mm wide cross-sectional elliptical polyester monofilament (cross-sectional shape 20 in FIG. 2A), weft 10
2 is a polyester monofilament having a circular cross section with a diameter of 0.7 mm and a high dry heat shrinkage ratio, and the paper contact side is 2
The weft was prepared to have a warp filling rate of 151.7% and a weft yarn density of 19.0 yarns / 2 / 2.54 cm. The manufactured dryer canvas has a thickness of 1.79 mm and a dimensional reduction rate of 8 in the thickness direction.
The air permeability was 9.5% and the air permeability was 2,101 cm ³ / cm ² · min.

(Example 6) The dryer canvas 150 of Example 6 was manufactured based on the specifications shown in Table 2 and the weave structure shown in FIG. That is, the warp 101 has a thickness of 0.
3 mm × 0.46 mm wide cross-sectional elliptical polyester monofilament (cross-sectional shape 20 in FIG. 2A), weft 10
2 is a polyester monofilament having a circular cross section with a diameter of 0.7 mm and a high dry heat shrinkage ratio, and the paper contact side is 2
It was manufactured with a weaving double weave structure with a 3/2 tear oblique and a 3/1 tear oblique on the paper surface side, a warp filling rate of 153.5%, and a weft density of 22.0 yarns / 2 / 2.54 cm. The manufactured dryer canvas has a thickness of 1.80 mm and a dimensional reduction rate of 9 in the thickness direction.
It was 0.0% and the air permeability was 1,511 cm ³ / cm ² · min.

In Examples 4 to 6, polyester monofilaments having an elliptical cross section were used for the warp, and the dry heat shrinkage rate was 12.1% at 160 ° C. and 19.0 at 180 ° C. for the weft.
%), The warp filling factor was higher than in Examples 1 to 3,
From 1.7% to 153.5%, the surface smoothness in the canvas width direction became better. In addition, since the paper contact side has a 2/2 tear oblique weft double weave structure in which the warp floats long, the surface smoothness in the canvas flow direction is good, and the contact area with the wet paper can be increased. done.

(Example 7) The dryer canvas 160 of Example 7 was manufactured based on the specifications shown in Table 3 and the weave structure shown in FIG. That is, the warp 101 has a thickness of 0.
Elliptical polyester monofilament having a cross section of 25 mm × width 0.5 mm (cross section 20 in FIG. 2A), weft 10
2 is a polyester monofilament having a diameter of 0.5 mm and a circular cross section and a high dry heat shrinkage, and the paper contact surface side is 2
The weft was prepared to have a warp filling rate of 174.8% and a weft yarn density of 25.5 yarns / 2 / 2.54 cm. The manufactured dryer canvas has a thickness of 1.23 mm and a dimensional reduction rate of 8 in the thickness direction.
The air permeability was 2.05%, and the air permeability was 1,095 cm ³ / cm ² · min.

In Example 7, a polyester monofilament having an elliptical cross section was used as the warp, and a monofilament having a high dry heat shrinkage (21.4% at 160 ° C. and 24.0% at 180 ° C.) was used as the weft. , The warp filling rate can be increased to 174.9%, the surface smoothness in the canvas width direction can be improved, and at the same time, the conventional warp in which the warp and the weft are composed of monofilaments can be achieved. Difficult, 1,095 cm ³ / cm ² ·
min low air permeability could be realized. Further, since the tension condition at the time of processing after weaving was set higher so that the warp yarn was entangled more strongly at the entanglement point with the weft, the dimensional reduction rate and the thickness in the thickness direction could be reduced.

Example 8 The dryer canvas 170 of Example 8 was manufactured based on the specifications shown in Table 3 and the weave structure shown in FIG. That is, the warp 101 has a thickness of 0.
35 mm × 0.7 mm width elliptical polyester monofilament in cross section (cross section 20 in FIG. 2 (A)), weft 10
2 is a polyester monofilament having a circular cross section with a diameter of 0.7 mm and a high dry heat shrinkage ratio, and the paper contact side is 2
It was manufactured with a weaving double weave structure having a 1/2 tearing oblique and a 3/1 tearing oblique on the paper side, a warp filling rate of 155.6%, and a weft density of 15.0 yarns / 2 / 2.54 cm. The manufactured dryer canvas has a thickness of 1.79 mm and a dimensional reduction rate of 8 in the thickness direction.
It was 5.0% and the air permeability was 13,982 cm ³ / cm ² · min.

In Example 8, a polyester monofilament having an oval cross section was used for the warp and a monofilament having a high dry heat shrinkage (12.1% at 160 ° C., 19.0% at 180 ° C.) was used for the weft. Was used, the warp filling rate could be further increased, and the surface smoothness in the canvas width direction became better. In addition, since the paper contact side has a 2/2 tearing oblique weft double weave structure in which the warp floats long,
The surface smoothness in the canvas flow direction was also good, and the contact area with the wet paper could be increased. Further, since the tension condition at the time of processing after weaving was set higher so that the warp yarn was entangled more strongly at the entanglement point with the weft, the dimensional reduction rate and the thickness in the thickness direction could be reduced.

Example 9 The dryer canvas 180 of Example 9 was manufactured based on the specifications shown in Table 3 and the woven structure shown in FIG. 8A. In other words, the warp 181 has a cross-sectional elliptical polyester monofilament having a thickness of 0.3 mm × width 0.46 mm (cross-sectional shape 20 in FIG. 2A), and the weft 182 has a circular cross-sectional dry heat having a diameter of 0.8 mm. Using a polyester monofilament having a high shrinkage ratio, the warp yarn is long floating on the side of the paper contacting side, and has a weaving single layer weave structure of 2/2 tear oblique, with a warp filling ratio of 135.6% and a weft yarn density of 15.5 yarns /
It was manufactured to 2.54 cm. The manufactured dryer canvas has a thickness of 1.33 mm and a dimension reduction ratio of 95.0 in the thickness direction.
% And an air permeability of 6,030 cm ³ / cm ² · min.

Example 10 The dryer canvas 190 of Example 10 was manufactured based on the specifications shown in Table 4 and the woven structure shown in FIG. 8B. In other words, the warp 191 has a dimension of 0.25 mm in thickness × 0.5 mm in width and has an elliptical cross-sectional shape of polyester monofilament (cross-sectional shape 2 in FIG. 2A).
0), a 3/1 broken oblique weft 1 in which a weft yarn 192 is a polyester monofilament having a circular cross section with a diameter of 0.6 mm and a high dry heat shrinkage ratio, and the warp is long-floated on the paper contact surface side.
With a heavy weave structure, the warp filling rate is 155.6% and the weft density is 25.
5 pieces / 2.54 cm. The manufactured dryer canvas has a thickness of 1.0 mm and a dimensional reduction rate of 9 in the thickness direction.
The air permeability was 0.5672 and the air permeability was 5,672 cm ³ / cm ² · min.

Example 11 The dryer canvas 200 of Example 11 was manufactured based on the specifications shown in Table 4 and the woven structure shown in FIG. 8B. That is, an elliptical polyester monofilament having a cross section of 0.35 mm in thickness × 0.7 mm in width (dimension 2 in FIG.
0), a 3/1 tear oblique weft 1 in which a weft yarn 192 is made of a polyester monofilament having a diameter of 1.0 mm and having a circular cross section and a high dry heat shrinkage ratio, and the warp floats long on the paper contact surface side.
With a heavy weave structure, the warp filling rate is 150.5% and the weft density is 15.
5 pieces / 2.54 cm. The manufactured dryer canvas has a thickness of 1.61 mm and a dimensional reduction rate of 9 in the thickness direction.
The air permeability was 4.7% and the air permeability was 7,325 cm ³ / cm ² · min.

In Examples 9 to 11, the polyester monofilament having an elliptical cross section was used for the warp, and the dry heat shrinkage was 12.1% at 160 ° C. and 19.0 at 180 ° C. for the weft.
%), The warp filling factor could be increased, and the surface smoothness in the canvas width direction became better. In addition, Examples 9 to
In No. 11, since a 2/2 or 3/1 torn single weave structure in which the warp floats long on the paper contact surface side, the surface smoothness in the canvas flow direction is also good, and the contact area with the wet paper Could be increased.

(Comparative Example 1) The dryer canvas 300 of Comparative Example 1 was manufactured based on the specifications shown in Table 5 and the woven structure shown in FIG. That is, the warp 101 has a diameter of 0.4
mm cross section circular polyester monofilament, weft 1
No. 02 is a weaving double weave structure with a cross-section circular polyester monofilament having a diameter of 0.6 mm and a cross-section of 2/2 torn on the paper contact side and 3/1 torn on the non-paper side, and a warp filling rate of 131.3. %, Weft density 17.4 yarns × 2 / 2.54c
m. The manufactured dryer canvas had a thickness of 1.89 mm, a dimensional reduction rate in the thickness direction of 94.5%, and a gas permeability of 15,612 cm ³ / cm ² · min.

Comparative Example 2 A dryer canvas 310 of Comparative Example 2 was manufactured based on the specifications shown in Table 5 and the weave structure shown in FIG. That is, the warp 101 has a diameter of 0.
3 mm circular cross-section polyester monofilament, the weft 102 has a diameter of 0.6 mm and a dry heat shrinkage of 160 ° C.
12.1% at 180.degree. C. and 19.0% at 180.degree. C., using a cross-sectional circular polyester monofilament having a high dry heat shrinkage ratio. The contact side is 2/2 torn and the anti-paper side is 3/1 torn. The warp filling ratio is 148.2% and the weft density is 1
It was manufactured to 8.3 pieces × 2 / 2.54 cm. The manufactured dryer canvas has a thickness of 1.59 mm, a dimensional reduction rate of 88.3% in the thickness direction, and an air permeability of 9,114 cm ³ / cm ² · m.
was in.

The dryer canvas of Comparative Example 2 has a good surface smoothness which has been used in a paper machine drying section for applications requiring a high quality level, such as papermaking of high quality paper and base paper for coating. It is a canvas having.

Comparative Example 3 A dryer canvas 320 of Comparative Example 3 was manufactured based on the specifications shown in Table 5 and the weave structure shown in FIG. That is, the warp 101 has a thickness of 0.
3 mm × 0.55 mm wide cross-section square polyester monofilament, the weft 102 has a diameter of 0.8 mm, a dry heat shrinkage of 12.1% at 160 ° C., and 19.0 at 180 ° C.
% Of polyester monofilament having a high cross-sectional dry heat shrinkage ratio, with a weaving double weave structure of 2/2 tear oblique on the paper contact side and 3/1 tear oblique on the anti-paper side, and a warp filling rate of 11
It was manufactured to 5.4% and a weft density of 14.0 yarns × 2 / 2.54 cm. The manufactured dryer canvas has a thickness of 2.06
mm, dimensional reduction rate in the thickness direction 93.6%, air permeability 11,
310 cm ³ / cm ² · min.

The dryer canvas of Comparative Example 3 has a wide width,
This canvas has been used in high-speed paper machine drying units.

Comparative Example 4 A dryer canvas 330 of Comparative Example 4 was manufactured based on the specifications shown in Table 6 and the woven structure shown in FIG. That is, the warp 101 has a thickness of 0.
3 mm × 0.55 mm wide cross-section square polyester monofilament, weft 102 having a diameter of 0.7 mm, dry heat shrinkage of 12.1% at 160 ° C., and 19.0 at 180 ° C.
% Of polyester monofilament having a high cross-sectional dry heat shrinkage ratio, with a weaving double weave structure of 2/2 tear oblique on the paper contact side and 3/1 tear oblique on the anti-paper side, and a warp filling rate of 11
It was manufactured with 5.1% weft density of 16.9 yarns x 2 / 2.54 cm. The manufactured dryer canvas has a thickness of 1.80.
mm, dimensional reduction rate in the thickness direction 90.0%, air permeability 6,0
70 cm ³ / cm ² · min.

The dryer canvas of Comparative Example 4 has a wide width.
This canvas has been used in high-speed paper machine drying units.

(Confirmation of rigidity in flow direction and width direction) The stiffness of the dryer canvases in Examples 1 to 11 and Comparative Examples 1 to 4 in the canvas flow direction (warp direction) and the canvas width direction (weft direction) was determined as described above. Was confirmed by a three-point bending stiffness test apparatus shown in FIG. The measurement was performed for each canvas with three samples, and the measurement results are shown in Table 7.

In each table, the PS (or BS) having three-point bending stiffness is defined as PS (or BS) when the direction in which the sample is loaded and pulled up is PS (or BS).
S). Therefore, the state where the wet paper is pressed on the cylinder when the canvas is used corresponds to the case where the weight is applied in the BS direction to pull up.

The measurement result of the three-point bending stiffness in the warp direction was 86.4 cN / 3 in Example 1 when the load direction was PS.
cm, 81.2 cN / 3 cm in Example 2, 7 in Example 3
9.7cN / 3cm, 92.2cN / 3c in Example 4
m, 100.8 cN / 3 cm in Example 5, 1 in Example 6
09.8cN / 3cm, 52.6cN / 3c in Example 7
m, 95.0 cN / 3 cm in Example 8, 9 in Example 9
5.1 cN / 3cm, 83.8 cN / 3c in Example 10
m and 108.2 cN / 3 cm in Example 11. On the other hand, in Comparative Example 1, 150.0 cN / 3 cm, in Comparative Example 2, 99.3 cN / 3 cm, and in Comparative Example 3, 101.5 cN / 3 cm.
/ 3 cm, and 106.8 cN / 3 cm in Comparative Example 4.

When the load direction is BS, 80.4 cN / 3 cm in the first embodiment and 81.1 cN / cm in the second embodiment.
3 cm, 74.8 cN / 3 cm in Example 3, 92.7 cN / 3 cm in Example 4, 95.4 cN / 3 c in Example 5
m, 105.3 cN / 3 cm in Example 6, 5 in Example 7
2.0cN / 3cm, 88.4cN / 3c in Example 8
m, 95.0 cN / 3 cm in Example 9, 8 in Example 10
2.1 cN / 3 cm, 106.0 cN / 3 in Example 11
cm. On the other hand, in Comparative Example 1, 116.7 cN / 3
cm, 76.2 cN / 3 cm in Comparative Example 2, 85.5 cN / 3 cm in Comparative Example 3, and 90.0 cN / cm in Comparative Example 4.
3 cm.

Therefore, the three-point bending rigidity in the warp direction is
110 cN / 3 cm or less for a double weft weave texture, weft 1
It was 110 cN / 3 cm or less in the heavy oblique weave structure, and it was confirmed that the flexibility in the warp direction was good. Furthermore,
A conventional canvas (Comparative Examples 2, 3, and 4) using a polyester monofilament having a circular cross section and a quadrangular cross section having the same dimension as the embodiment in the thickness direction of the warp in the warp,
When Examples 2, 1, 3, and 4 having the same air permeability as those were compared, it was found that the flexibility in the warp direction was extremely good.

Next, the measurement result of the three-point bending stiffness in the weft direction is 930.3 in Example 1 when the load direction is PS.
cN / 3 cm, 875.5 cN / 3 cm in Example 2, 964.2 cN / 3 cm in Example 3, and 107 in Example 4.
0.7 cN / 3 cm, 1180.3 cN / 3 in Example 5
cm, 1284.8 cN / 3 cm in Example 6, Example 7
502.9 cN / 3 cm in Example 8, 837.3 cN in Example 8
/ 3 cm, 601.8 cN / 3 cm in Example 9, 501.2 cN / 3 cm in Example 10, and 785 in Example 11.
It was 4 cN / 3 cm. On the other hand, in Comparative Example 1, 627.
1 cN / 3 cm, 661.9 cN / 3 c in Comparative Example 2
m, 888.9 cN / 3 cm in Comparative Example 3, and 830.7 cN / 3 cm in Comparative Example 4.

When the load direction was BS, 924.7 cN / 3 cm in Example 1 and 876.3 cN in Example 2
N / 3 cm, 969.9 cN / 3 cm in Example 3, 1068.7 cN / 3 cm in Example 4, and 112 in Example 5.
9.7 cN / 3 cm, 1282.4 cN / 3 in Example 6
cm, 501.4 cN / 3 cm in Example 7, 832.2 cN / 3 cm in Example 8, and 601.7 cN / cm in Example 9.
3 cm, 500.5 cN / 3 cm in Example 10, and 769.7 cN / 3 cm in Example 11. On the other hand, in Comparative Example 1, 665.1 cN / 3 cm, and in Comparative Example 2, 668.
0 cN / 3 cm, 930.8 cN / 3 c in Comparative Example 3
m and 869.9 cN / 3 cm in Comparative Example 4.

Therefore, the three-point bending rigidity in the weft direction is
500 cN / 3 cm or more for a double weft weave structure, weft 1
It was 500 cN / 3 cm or more in the heavy oblique weave structure, and it was confirmed that the rigidity in the weft direction was high. Furthermore, the three-point bending stiffness in the weft direction of a conventional canvas (comparative examples 1 and 2) using a circular cross-section polyester monofilament for the warp and the weft is the same as that of Example 1 having air permeability equivalent to those.
2 was confirmed to be significantly higher. In addition, when comparing the conventional canvas (Comparative Example 4) in which the dimension in the canvas thickness direction of the warp and the diameter dimension of the weft are the same as the example with Examples 3 and 4 having the same air permeability as the example, the weft is It was found that the three-point bending stiffness in the directions was extremely good.

The dryer canvases of Comparative Examples 3 and 4 have been used in a wide and high-speed paper machine drying section.

(Evaluation of Running Stability) Examples 1 to 1
The deviation angles before and after heating of the dryer canvases of Comparative Example 1 and Comparative Examples 1 to 4 were measured by the deviation angle measuring device shown in FIG. 4 to estimate the deviation of the woven structure during running on the canvas. The running stability was evaluated. The measurement was performed on each canvas with a sample number of 3, and the measurement results are shown in Table 8.

The shift angle before heating was 2.10 in Example 1.
°, 1.70 ° in Example 2, 1.35 ° in Example 3, 1.02 ° in Example 4, 0.60 ° in Example 5, and Example 6.
0.51 ° in Example 7, 2.15 ° in Example 7, and 2.15 in Example 8.
21 °, 1.52 ° in Example 9, and 1.83 in Example 10.
° and 1.48 ° in Example 11. On the other hand, Comparative Example 1
Was 2.16 °, Comparative Example 2 was 1.00 °, Comparative Example 3 was 2.01 °, and Comparative Example 4 was 1.00 °.

The deviation angle after heating was 5.08 in Example 1.
°, 3.97 ° in Example 2, 2.72 ° in Example 3, 2.37 ° in Example 4, 1.49 ° in Example 5, and Example 6.
1.22 ° in Example 7, 4.71 ° in Example 7, and 5 in Example 8.
33 °, 2.49 ° in Example 9, and 2.85 in Example 10.
° and 2.33 ° in Example 11. On the other hand, Comparative Example 1
Was 4.78 °, Comparative Example 2 was 2.58 °, Comparative Example 3 was 5.33 °, and Comparative Example 4 was 2.59 °.

Therefore, a conventional canvas (comparative examples 3 and 4) using a warp with a rectangular cross section monofilament having the same dimension in the canvas thickness direction as that of the embodiment,
When Examples 1 and 4 having the same air permeability are compared with each other, the deviation angles before and after heating are almost equal to or smaller than those of a conventional canvas having a quadrangular cross-sectional monofilament. It was found that the running stability of the vehicle was maintained or improved.

The dryer canvases of Comparative Examples 3 and 4 have been used in a wide and high-speed paper machine drying section.

(Evaluation of Surface Smoothness in Flow Direction and Width Direction) The coefficient of static friction in the flow direction (warp direction) and width direction (weft direction) of the dryer canvases of Examples 1 to 6 and Comparative Examples 1 to 4 described above. The kinetic friction coefficient was measured by the measuring device shown in FIG. 5 to evaluate the surface smoothness in the flow direction and the width direction. The measurement was performed using three samples for each canvas, and the measurement results are shown in Table 9.

The coefficient of static friction in the warp direction was 0.1 in Example 1.
176, 0.176 in Example 2, 0.18 in Example 3
2, 0.166 in Example 4, 0.165 in Example 5, and 0.162 in Example 6. On the other hand, in Comparative Example 1, the value of 0
195, 0.203 in Comparative Example 2 and 0.2 in Comparative Example 3.
01 and 0.202 in Comparative Example 4.

The coefficient of dynamic friction in the warp direction was 0.1 in Example 1.
259, 0.278 in Example 2, and 0.28 in Example 3
3, 0.256 in Example 4, 0.251 in Example 5, and 0.250 in Example 6. On the other hand, in Comparative Example 1, the value of 0
261; 0.294 in Comparative Example 2;
90 and Comparative Example 4 had a value of 0.288.

The coefficient of static friction in the weft direction was determined in Example 1.
0.179 in Example 2, 0.178 in Example 2, and 0.1 in Example 3.
182, 0.176 in Example 4, 0.17 in Example 5
0 and 0.167 in Example 6. On the other hand, it was 0.189 in Comparative Example 1, 0.214 in Comparative Example 2, 0.207 in Comparative Example 3, and 0.202 in Comparative Example 4.

The coefficient of kinetic friction in the weft direction was determined in Example 1.
0.288 in Example 2, 0.270 in Example 2, and 0.3 in Example 3.
251; 0.251 in Example 4; 0.25 in Example 5
7. In Example 6, the value was 0.238. On the other hand, it was 0.243 in Comparative Example 1, 0.275 in Comparative Example 2, 0.319 in Comparative Example 3, and 0.314 in Comparative Example 4.

Therefore, compared to a conventional canvas (Comparative Example 2) in which small diameter circular cross-section polyester monofilaments are arranged in the warp at a high density and which is suitable for applications requiring a high quality level, the air permeability is the same. When Example 2 is compared, both the static friction coefficient and the dynamic friction coefficient in the canvas flow direction (warp direction) and the canvas width direction (weft direction)
Both of the static friction coefficient and the dynamic friction coefficient were extremely good results, and it was found that the examples had excellent surface smoothness in both the flow direction and the width direction of the canvas. Further, a conventional canvas having a quadrangular cross-section polyester monofilament disposed on the warp and having good surface smoothness (Comparative Example 3,
In contrast to 4), Examples 1, 3, and
In comparison with Comparative Example No. 4, both the static friction coefficient and the dynamic friction coefficient in the canvas flow direction (warp direction) and the static friction coefficient and the dynamic friction coefficient in the canvas width direction (weft direction) are extremely good. Was confirmed to be a canvas having excellent surface smoothness in both the flow direction and the width direction.

[0114]

[Table 1]

[0115]

[Table 2]

[0116]

[Table 3]

[0117]

[Table 4]

[0118]

[Table 5]

[0119]

[Table 6]

[0120]

[Table 7]

[0121]

[Table 8]

[0122]

[Table 9]

[0123]

According to the present invention, in a papermaking dryer canvas made of a synthetic fiber woven fabric, a warp yarn is filled with a monofilament having an elliptical cross section so that its major axis direction becomes the canvas width direction. Rate is 100% ~ 17
Since it is within a high range of 5%, the filling rate of the warp is 130% to 175% by using a monofilament having a high dry heat shrinkage rate for at least one weft constituting the woven fabric.
Therefore, it can be suitably used in applications requiring a high quality level, such as papermaking of high quality paper and base paper for coating, and comparison of the moisture content of wet paper in the drying section of a paper machine for those uses. It is possible to realize a papermaking dryer canvas having extremely good surface smoothness and flexibility in the warp direction which can be particularly preferably used in the front group having a high height, and having sufficient rigidity in the weft direction.

Furthermore, it is possible to achieve a thickness applicable to a drying section of a single-run canvas type or a type in which cylinders are arranged in a single row, and at the same time, to have excellent dimensional stability applicable to a wide and high speed paper machine. Thus, it is possible to realize a papermaking dryer canvas having excellent properties, running stability, and a wide range of air permeability adjustment.

Further, a low air permeability of 1,095 cm ³ / cm ² · min, which was difficult to achieve with a conventional dryer canvas in which the warp and the weft are composed of monofilaments, can be achieved.

[Brief description of the drawings]

FIG. 1 shows an example of a canvas weave structure to which the present invention can be applied.
(D) is a weft single-layer oblique weave structure diagram, each showing a structure in which the warp floats long.

FIGS. 2A, 2B, and 2C are cross-sectional views showing examples of a substantially elliptical cross section of a monofilament used in the present invention.

FIG. 3 is an explanatory view of a three-point bending rigidity measuring device for a canvas sample.

FIG. 4A is an enlarged explanatory view of a measurement pointer in a canvas sample displacement angle measuring device, and FIGS. 4B and 4C are state diagrams before and after measurement of the canvas sample displacement angle measuring device.

FIG. 5 is an explanatory view of an apparatus for measuring a static friction coefficient and a dynamic friction coefficient of a canvas sample.

FIG. 6A is a sectional view showing a problem when a conventional monofilament having a square cross section is used for a canvas warp;
(B) is sectional drawing which shows the advantage at the time of using the monofilament of an elliptical cross section of this invention for a canvas warp.

FIG. 7 is a canvas organization diagram of a weft double weave used in Examples and Comparative Examples of the present invention.

FIGS. 8A and 8B are canvas organization diagrams of a single weave weave used in Examples of the present invention.

[Explanation of symbols]

10, 100, 110, 120, 130, 140, 15
0, 160, 170, 180, 190, 200, 30
0, 310, 320, 330 ··· Dryer canvas 11, 101, 181, 191 ··· Warp 12, 102, 182, 192 · · · Weft 13 · · · paper contact side 14 · · · anti-contact paper side 20 · · oval 22 , 24, roughly elliptical 23, straight section 25, arc-shaped corner drop section 70, warp 71, canvas surface

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L048 AA19 AA20 AA37 AA50 AB10 BA01 BA02 BA11 BC00 CA11 CA15 DA39 4L055 CF27 CF28 CF30 EA15 EA19 FA14 GA17 GA19

Claims (10)

[Claims] 1. A papermaking dryer canvas made of a synthetic fiber woven fabric, wherein a monofilament having an elliptical cross section is arranged in a warp so that a major axis direction thereof becomes a canvas width direction, and a warp filling ratio is 100% or more. A papermaking dryer canvas characterized by being in the range of 175%. 2. The filling rate of a warp is in a range of 130% to 175% by using a monofilament having a high dry heat shrinkage rate for at least one weft constituting the woven fabric. Dryer canvas for papermaking. 3. The woven fabric is a woven fabric having a weft double oblique weave structure in which at least the warp yarn on the surface side of the paper contact surface is long floating. 35m
2. A monofilament having an elliptical cross section and having a size of mx 0.40 mm to 0.70 mm and a ratio of a minor axis to a major axis of 1: 1.6 to 1: 2.
Or the papermaking dryer canvas according to 2. 4. The contact side weft and the non-contact side weft,
Each is a monofilament with a circular cross section having a diameter in the range of 0.4 mm to 0.8 mm, and a weft density of 15 × 2 / 2.54 cm to 48 × 2 / 2.54c.
4. The papermaking dryer canvas according to claim 3, wherein m is in the range of m. 5. The warp and the weft are woven using polyester monofilaments, the dimensional reduction rate in the canvas thickness direction is in the range of 82.0% to 90.0%, and the canvas thickness is 1.23 mm. The papermaking dryer canvas according to any one of claims 1 to 4, wherein the thickness is within the range of ~ 1.8 mm. 6. A warp and a weft are woven using a PPS monofilament, and a dimensional reduction rate in a canvas thickness direction is 8%.
The papermaking according to any one of claims 1 to 4, wherein the paper is in a range of 4.0% to 92.0%, and the thickness of the canvas is in a range of 1.26 mm to 1.85 mm. For dryer canvas. 7. The woven fabric is a woven fabric having a single weft oblique weave structure in which at least a warp on the surface on the side of the paper contact surface is long floating, and the warp has a minor axis × major axis of 0.25 mm to 0.2 mm. 35m
2. A monofilament having an elliptical cross section and having a size of mx 0.40 mm to 0.70 mm and a ratio of a minor axis to a major axis of 1: 1.6 to 1: 2.
3. The papermaking dryer canvas according to any one of to 2 above. 8. Each of the wefts has a diameter of 0.6 mm or more.
A monofilament having a circular cross section in the range of 1 mm and a weft density of 15 yarns / 2.54 cm to 35 yarns /
8. The method according to claim 7, wherein the distance is within 2.54 cm.
A paper dryer canvas as described. 9. The warp and the weft are woven using polyester monofilaments, the dimensional reduction rate in the canvas thickness direction is in the range of 90.5% to 95.0%, and the canvas thickness is 1.0 mm. The papermaking dryer canvas according to any one of claims 1, 2, 7, and 8, wherein the diameter is within a range of from 1.61 mm. 10. The warp and the weft are woven using PPS monofilament, the dimensional reduction rate in the canvas thickness direction is in the range of 93.6% to 97.0%, and the canvas thickness is 1.03 mm. The papermaking dryer canvas according to any one of claims 1, 2, 7, and 8, wherein the thickness is within a range of from 1.65 to 1.65 mm.