JPH11301825A - Pressurized belt for bonding paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb slacks in the width direction caused by belt tension mottles and irregularities on the surface of liner paper and to uniformize the bonding in the width direction between a belt, the paper and a roll by providing an elastic layer in the thickness direction of the pressurized belt. SOLUTION: No-twist thread of para-Aramid fibers are used for a warp and a weft to weave a woven fabric 2 into a bag shape, para-Aramid-fibers of 200 g/m<2> are laminated on both faces of the woven fabric 2 used as a core body to form a curd web, and the curd webs are integrally slipped by needle punching to form needle felts 3, 4. The surface and back webs are coated with a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer resin of 420 g/m<2> , then it is dried at 80 deg.C. This belt is applied with a pressing process by a flat plate heat press machine under the conditions of 350 deg.C×10 kg/cm<2> ×20 min to obtain an endless felt belt 1, thereby an elastic layer having a pressure change quantity of 100 μm or above and a nonwoven fabric layer formed on it and having the hardness of 85 deg. or above are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure belt used in a corrugating machine of a single-sided corrugated paperboard production line.

[0002]

2. Description of the Related Art A conventional single-faced corrugated cardboard manufacturing apparatus is provided with a pair of heatable corrugated rolls, a gluing mechanism, and a lower corrugated roll, which are provided with a corrugated corrugation in the circumferential direction and are installed so as to mesh with each other. The core paper, which is composed of possible press rolls and is stepped by the step rolls, is coated with starch paste on the top of the step, then guided to the press rolls, and liner paper supplied from the press roll side. ,
Pressed and dried between the press roll and lower roll,
It becomes a single-sided cardboard.

However, this pressing method using a press roll has the following disadvantages. (1) It is difficult to adjust the pressing force and the gap between the press roll and the step roll, transfer of a press mark to the paper surface, breakage of the liner paper, and the like are likely to occur, and the yield is poor. . (2) The adhesive strength is unstable. (3) The frequency of adjustment is high and it takes time. (4) Noise and vibration are large. Such problems have been pointed out, and in recent years, a device using a pressure contact method by a belt press type has been adopted. As a belt used in the apparatus, a steel belt was initially used, but recently, a woven belt using high-strength fiber yarn has been used from the viewpoint of safety.

[0004]

The pressure belt used in the single-sided corrugated cardboard manufacturing apparatus can maintain the adhesion between the belt, paper, and rolls in the width direction as uniform as possible due to its wide characteristic. This is an important point related to cardboard quality and productivity.

As one of the countermeasures, a method of increasing the rigidity in the belt width direction has been considered, and the following method has been devised and disclosed. a) The warp / weft morphology and weave structure of the woven fabric are changed. (Japanese Unexamined Patent Publication No. Hei 6-107311 and Japanese Unexamined Patent Publication No. Hei 7-35414) b) Laminating reinforcing yarn and cloth in the width direction. (JP-A-7-315533, JP-A-8-81029, and JP-A-8-108913) c) A reinforcing material is embedded in the resin layer. However, in any case, an important point as a pressure belt used in a single-sided corrugated cardboard manufacturing apparatus is to maintain flexibility in a belt circumferential direction to withstand bending during traveling. However, there are problems such as insufficient rigidity in the belt width direction, durability, and irregularities on the product.

Therefore, conventionally, a method of applying a high tension to the belt and pressing the paper / roll with the belt to eliminate the influence of the unevenness on the surface of the liner paper and bringing the belt into close contact has been adopted. That is, in the conventional belt, the belt tension distribution is stabilized,
Very high tension is required to absorb the irregularities on the liner paper surface and increase the adhesion, and if the belt itself is warped or twisted, extra extra tension is needed to correct it. It was necessary to apply tension. for that reason,
The tensile strength required for the belt is extremely high, and as a result, there is a problem in that the life of the belt is shortened, and the cost is increased by increasing the strength of the woven fabric serving as the core.

Further, the conventional belt has a structure mainly composed of a woven fabric core portion which maintains tensile strength, and a front surface and a back surface portion which maintain high hardness for preventing the belt from biting by the step roll during pressing. And almost no elasticity in the thickness direction.

The present invention has been made in consideration of the above problems, and in a pressure belt used in a single-sided corrugated cardboard manufacturing apparatus, a layer having elasticity in a thickness direction is provided on a part of its structure to reduce belt tension unevenness. The purpose of the present invention is to absorb slack in the width direction and unevenness on the surface of the liner paper, and to uniformize the pressure contact between the belt, the paper, and the roll in the width direction.

[0009]

Means for Solving the Problems The present invention adopts the following constitution to solve the above-mentioned problems. FIG. 1 is an overall perspective view of a belt according to the present invention. This belt 1 is suspended between a pair of heatable pulleys in a corrugated cardboard manufacturing apparatus, and a part of the belt has a circumferential surface stepped in a corrugated shape. This is pressed against a pair of heatable step rolls, which are installed so as to mesh with each other, in an arc shape, and rotates. The liner paper is fed between the belt 1 and the step roll, is superimposed on the core paper sent from the step roll side after being molded and glued, and is pressed and dried to form a single-sided cardboard.
At this time, the tension applied to the belt acts as a surface pressure at a pressure contact portion between the belt and the step roll, and the surface pressure is several k.
g / cm ² .

When the liner paper and the core are pressed, the belt 1
The elastic layers 3 and 4 in the thickness direction correct unevenness of the pressurized surface caused by belt tension unevenness, and absorb small press-contact unevenness due to unevenness of the liner paper to make the adhesion in the width direction uniform and stable. It enables a bonded state and a high bonding strength. Further, even when the pressing force is partially biased in the width direction, the elastic layers 3 and 4 absorb the pressure and can prevent troubles such as formation of marks on the corrugated cardboard surface. Further, in the conventional belt, the unevenness of the belt tension, which was adjusted by applying a high tension, can be covered by the elastic layer, so that the belt tension does not need to be increased more than necessary, and the life of the belt and the machine life can be increased. Life can be extended.

FIGS. 2 and 3 show the sectional structure of the belt according to the present invention. The elastic layers 3 and 4 are divided into the following three. (A) Non-woven fabric layer (b) Elastomer layer (c) Elastic woven layer (multi-layer woven fabric, etc.) At least a part of the belt cross-sectional structure contains at least one of (a) to (c) elastic layers. Is the feature. Also,
Two or more elastic layers may be combined and laminated. For example, an elastomer layer may be provided on the nonwoven fabric layer, or an elastomer layer may be provided on one side and a nonwoven fabric layer may be provided on the other side. Furthermore, it is also possible to impregnate the nonwoven fabric layer with resin, rubber, etc. to form an elastic layer. Further, as the elastic fabric layer, a multi-woven fabric such as a three-dimensional fabric is particularly desirable.

The elastic layers 3 and 4 are portions having a pressure displacement of 100 μm or more measured by a method described later, and the following materials are preferable as constituent materials. (A) Fiber: aromatic polyamide (meta- and para-aramid), polyetheretherketone (PEEK), polyimide, polyparaphenylenebenzobisoxazole (PBO), polyphenylene sulphite (PPS) (b) Elastomer: acrylic rubber -Epichlorohydrin rubber-ethylene-acrylate copolymer rubber-fluorine-based and silicon-based rubber and mixtures thereof. When the amount of pressure displacement is 100 μm or less, the effect of correcting uneven belt tension and absorbing the unevenness of paper becomes insufficient. Further, when a non-heat-resistant material other than the above-mentioned material is used as the elastic layer, the displacement amount decreases and declines in a short time, and cannot be used for a long time.

The fabric 2 serving as the core is desirably made of the following materials, taking into account the tensile strength and heat resistance in the circumferential direction of the belt. (Warp) Organic / inorganic heat-resistant, high-strength, high-modulus fiber such as para-aramid, polyparaphenylenebenzobisoxazole (PBO), glass fiber, and carbon fiber. (Weft) Para-aramid, polyarylate, polyetheretherketone (PEEK), PBO, glass fiber,
Organic and inorganic heat-resistant fiber yarns such as carbon fiber, meta-aramid, and polyphenylene sulfite (PPS). In particular, a high-strength high-modulus fiber yarn is essential for the warp in the belt circumferential direction, and organic high-strength high-modulus fiber yarns such as para-aramid fibers and PBO fibers are desirable in view of bending resistance. .

The non-woven fabric is a fiber laminate such as (a) a short-fiber non-woven fabric made by a conventionally known method such as a carding web, (b) a spun-bonded non-woven fabric, and (c) a spun lace.

The lamination and integration of the woven fabric and the nonwoven fabric can be appropriately selected from the following and used. (A) Mechanical entanglement of needle punching (b) Adhesion or thermal adhesion with adhesive resin

The structure of the belt according to the present invention can be roughly divided into two types.
It is to include at least one or more elastic layers. (1) The elastic layer is formed by laminating and integrating one side or both sides of a core made of a woven fabric made of heat-resistant fibers (see FIG. 2). (2) The elastic layer is sandwiched between woven fabrics made of heat-resistant fibers (see FIG. 3).

Further, in any of (1) and (2), it is desirable that a belt or a heat-resistant and non-adhesive resin or rubber layer such as fluorine or silicon is laminated and integrated on the front and back surfaces of the belt. The resin / rubber layer improves the surface smoothness of the corrugated cardboard, suppresses unnecessary intrusion of the belt into the corrugated roll, and prevents the formation of marks on the corrugated cardboard surface. Therefore, the hardness of the resin / rubber layer is desirably 85 ° or more (JIS-A type hardness meter). In addition, the belt 1 in which the elastic layer is integrated with a fabric can be impregnated with the heat-resistant and non-adhesive resin or rubber. This makes it possible to adjust the amount of pressurized displacement of the elastic layer and its continuity, and to adjust the overall rigidity. The solid content of the resin or rubber to be impregnated is 10 to 70 wt.
% Is desirable.

Further, as a substitute for the resin and rubber on the front and back surfaces of the belt, a non-woven fabric whose main material shown below is made of a heat-adhesive fiber can also be used. By subjecting the heat-adhesive fibers to a heat press treatment at a temperature equal to or higher than the glass transition point, the heat-adhesive fibers constituting the nonwoven fabric are heat-bonded at their entangled points, and the molecular structure increases in rigidity. If a non-woven fabric layer for high density and smoothness is laminated and integrated and heat-treated, the required properties of the belt of the present invention, namely (a) smoothness (b) abrasion resistance (c) (D) Stain prevention property (e) Hardness can be obtained. Examples of the heat-adhesive fiber material include polyallylate, polyetherimide, PPS and undrawn yarn thereof, and meta-aramid undrawn yarn. As the hot pressing conditions, for example, when polyarylate fiber is used as the heat-adhesive fiber material, at a temperature of 180 to 300 ° C. which is equal to or higher than the glass transition point, and a pressure of 5 to 50 kg / cm ² , the pressure is 10 seconds to 10 seconds. It is desirable to treat for 20 minutes,
As a result, the nonwoven fabric layer made of the heat-adhesive fiber as the main material on the front and back surfaces is densified and smoothed, and the above-described front and back surface functions can be imparted.

The method of laminating and integrating the elastomer layer and the woven fabric core is performed by directly applying the elastomer onto the woven fabric or by heat bonding a sheet-like material. Further, the method of laminating and integrating the elastic woven fabric layer and the woven fabric serving as the core is performed by heat fusion and bonding with a heat-resistant resin adhesive therebetween. Examples of the heat-resistant resin adhesive include P
Fluorocarbon resins and rubbers represented by TFE,
Silicone resins and rubbers, and mixtures of both, polyimide, PPS, polyetherimide, PEEK, polyamideimide, polysulfone, polyethersulfone, and other resins and acrylic rubber, epichlorohydrin rubber, ethylene-acrylate copolymer rubber, and the like. .

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In a woven fabric core, heat-resistant, high-strength, and high-modulus yarns are used as the constituent yarns in the circumferential direction of the belt to satisfy heat resistance and tensile strength in a high-temperature use environment. It is possible to suppress the load and withstand the load on the belt during the production of corrugated cardboard, and to ensure the running stability.

By providing at least one layer having elasticity in the thickness direction in a part of the belt production, when the liner paper and the core paper are pressed against each other, the elastic layer has uneven pressure surface pressure generated by uneven belt tension. In addition, it absorbs small uneven spots due to irregularities on the surface of the liner paper, performs uniform pressure bonding in the belt width direction, and obtains stable adhesion and strong adhesion of corrugated paper.

An elastic layer having a displacement of 100 μm or more and a heat-resistant resin / rubber having a hardness of 85 ° or more formed on the elastic layer, or a main material which has been densified and smoothed by heat treatment has a thermal adhesive property. Even when the pressure is biased in a part of the width direction due to the nonwoven fabric layer made of fibers, absorb the pressure and suppress the belt from being unnecessarily biting into the corrugated roll, and transfer it as a corrugated cardboard surface mark. To prevent

By the elastic layer, the adhesion between the belt and the paper / roll can be increased without unnecessarily increasing the belt tension.

Hereinafter, description will be made based on embodiments. (Example 1) Para-aramid fiber (trade name: Kevlar)
Non-twisted yarn of DuPont Toray Kevlar Co., Ltd.) is used for warp and weft (1500d), and a woven fabric woven in a sachet structure in a bag shape is used as a core. Para-aramid short fibers (trade name: Kevlar) 1.5d x 51mm) 200g each
/ M ² were entangled and integrated by needle punching (needle density: 2100 needles / in ² , needle needle depth: 12 mm) to obtain a needle felt. After applying 420 g / m ^{2 of a} tetrafluoroethylene / perfluoroalkylvinyl ether copolymer resin (PFA resin, trade name: NEOFLON AD-2CR, manufactured by Daikin Industries, Ltd.) on the front and back webs,
And dried. This belt is pressed by a flat plate type heat press
Press processing was performed under the conditions of 50 ° C. × 10 kg / cm ² × 20 minutes to obtain an endless felt belt. Table 1 shows the detailed configuration.

[0023]

[Table 1]

(Example 2) The same woven fabric as in Example 1 was used as a core, and the same card web of 200 g / m ² as in Example 1 was laminated on both surfaces thereof, and entangled and integrated by needle punching. Further, from above, an aromatic polyester staple fiber (trade name: Vectran 2.5d × 51mm, manufactured by Rare Corporation)
200 g / m ^{2 of} card web was laminated on each of the front and back sides, and needle punching (needle density: 2550)
Needle / in ² , needle needle depth: 10 mm) to obtain a needle felt. To this belt, PF
A resin (trade name: NEOFLON AD-2CR)
The squeezing was adjusted so that the solid content of the adhered resin became 10 wt%, and then drying was performed at 80 ° C. for 30 minutes. This was treated in a drying oven of hot air circulation type at 350 ° C. × 20 minutes, and then pressed by a flat plate type hot press under the conditions of 200 ° C. × 20 kg / cm ² × 15 minutes to obtain an endless state. Got a felt belt.

(Example 3) A nonwoven fabric of para-aramid fiber (trade name: Kevlar) is used for warp and weft (3000d) to form a weft weave (A). : 540 g / m by Viton Dupont
^{2 was} applied and dried at 80 ° C. From above, non-twisted para-aramid fiber (trade name: Kevlar) is wrapped with warp and weft (1
400d), the plain woven fabric (B) is heated at 350 ° C. × 20 kg / cm × 0.5 m /
The endless belt was obtained by laminating and integrating the woven fabric (A) and the woven fabric (B). PFA resin (trade name: NEOFLON AD-2CR) on both sides of this belt
Was applied at 420 g / m ² , dried at 80 ° C., and further heated at 350 ° C. × 10 kg / c with a flat-plate-shaped heat press.
Press processing was performed under the conditions of m ² × 20 minutes to obtain an endless belt.

(Example 4) On one surface of the same woven fabric as in Example 1, a three-dimensional woven fabric made of a meta-aramid fiber yarn (trade name: manufactured by Conex Teijin Limited) was placed between the two to a thickness of 5 mm.
0 μm FEP film (trade name: NEOFLON NF-0)
050) and 300 ° C x 20 with a hot roll press
The thermocompression bonding was performed under the condition of kg / cm × 0.5 m / min and integrated. Furthermore, a thickness of 20 on both sides of the obtained endless belt.
0 μm FEP film (trade name: NEOFLON NF-
0200) at 300 ° C x 10k with a flat-plate type heat press
Press processing was performed under the conditions of g / cm ² × 10 minutes, and heat fusion was performed to obtain an endless belt.

Comparative Example 1 In the same manner as in Example 1, a felt belt was prepared. At this time, the flat-plate-type hot pressing condition was changed from 350 ° C. × 10 kg / cm ² × 20 minutes of Example 1 to 3
The temperature was changed to 50 ° C. × 80 kg / cm ² × 20 minutes to obtain an endless felt belt in which the porosity of the elastic nonwoven fabric layer was 15%. (The porosity of the elastic nonwoven fabric layer of Example 1 is 65
%)

Comparative Example 2 Using the same woven fabrics (A) and (B) as in Example 3, a 500 μm thick F
EP film (product name: NEOFLON NF-0500)
300 ° C x 20kg using a hot roll press
/Cm×0.5 m / min to obtain an endless belt which was thermally fused and laminated and integrated. After applying 420 g / m ² of FEP resin (trade name: MDF-120J) to both sides of the belt, drying was performed at 80 ° C., and further, at 300 ° C. × 20 kg / cm ² × 20 minutes using a flat plate type heat press. Under the following conditions to obtain an endless belt.

(Comparative Example 3) A nonwoven fabric of para-aramid fiber (trade name: Kevlar) was used as warp and weft (3000d) and woven into a bag with a flat structure on one side of PTFE.
A resin (trade name: MDF-30J, manufactured by Mitsui DuPont Fluorochemicals Co., Ltd.) is applied at 300 g / m ² and dried at 80 ° C., and then the other side is coated with 700 PTFE resin.
g / m ^{2 was} applied and dried at 80 ° C., and then heat-treated at 350 ° C. × 5 minutes in a hot-air circulation type drying furnace. Further, a press treatment was performed with a hot roll press under the conditions of 300 ° C. × 20 kg / cm × 2 m / min to obtain an endless belt having a smooth surface. Table 2 shows the results.

[0030]

[Table 2]

In Examples 1 to 4, the amount of pressure displacement in the belt thickness direction was 100 μm or more.
It shows high retention even after aged press at 80 ° C. × 20 kg / cm ² × 100 hr. When the belt of the present invention having a width of 2 m is incorporated into a single-sided corrugated cardboard manufacturing apparatus and used, compared with a conventional belt having no elastic layer as shown in Comparative Example 3, even with a belt tension of 2/3, the belt extends over the entire width of the belt. And good adhesion to paper and rolls. The obtained cardboard had sufficient adhesive strength and no mark on the surface was observed.

On the other hand, in Comparative Example 1, a desired amount of pressure displacement was not obtained because the apparent density of the elastic nonwoven fabric layer was too high, and in Comparative Example 2, the belt thickness of the FEP resin layer as the elastic layer was changed. Since the amount of displacement in each of the directions was as small as less than 100 μm, the belt tension was not reduced. Comparative Example 3 had the same results as Comparative Example 2.

The properties of the examples and comparative examples were measured by the following methods and conditions. (1) Strong elongation, strength at 2.5% elongation: Instron tensile tester JIS L-1096 (General woven fabric test method) 6.12. A
Follow the law. (2) Flexural rigidity: A sample of 30 W × 250 L is installed as shown in FIG. 4, and the bending rigidity is determined by the following formula from the amount of deflection of the sample tip when a load is applied to a predetermined position. Flexural rigidity = WL ³ / (3 (T / 2)) (3) Hardness: JIS-A type hardness meter JIS K-6301 (Vulcanized rubber physical property test method) 5.2.
2 (spring hardness test). (4) Abrasion loss: Taper type abrasion tester Abrasion wheel: H-
18 Load: 1000 g Evaluated by weight loss value (mg) after abrasion 3000 times According to JIS L-1096 6.17.3C method. (5) Stain removal property: 100% starch paste on sample surface
g / m ² and dried, then peeled off from the sample,
Visual evaluation of peeling state at that time [Evaluation] 〇: Easy peeling Δ: Force is required to peel off ×: Adhesive adheres to sample surface and remains (6) Smoothness: Evaluated by visual and tactile sensation [Evaluation] 〇: No fuzziness Δ: Fuzzy when rubbed X: Fuzzy (7) Amount of applied pressure: 180 ° C., 0.2 to 4 kg / cm ²
Amount of change in thickness between loads is measured by a flat plate type heat press machine in accordance with the following procedures. Initial state of sample and 180 ℃ × 2
After the deterioration press of 0 kg / cm ² × 100 hr, measurement and evaluation are performed. Applying a load of 0.2 kg / cm ² and measuring the sample thickness one minute later. A load of 4 kg / cm ² is applied next, and the sample thickness after one minute is measured. And the thickness difference is obtained (at the time of pressurization). Return the load to 0.2 kg / cm ² and measure the sample thickness one minute later. ; And the thickness difference (when depressurized). (7) Porosity: Porosity (%) = 1− (apparent density of elastic layer / fiber true density)

[0034]

The effects of the product of the present invention are summarized as follows. (1) The belt and the paper / roll can be uniformly bonded in the width direction, the adhesive strength is increased, and the quality and productivity of the cardboard are improved. (2) The transfer of marks to the surface of the cardboard can be prevented by the elastic layer and the front and back layers, and the yield is improved. (3) There is no need to apply extra tension to the belt, and the belt life is extended. Also, the machine load can be reduced, and the machine life can be extended. Maintenance work is also reduced.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a paper bonding pressure belt showing an embodiment according to the present invention.

FIG. 2 is a sectional view of a pressure belt for bonding paper showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a pressure belt for bonding paper showing another embodiment of the present invention.

FIG. 4 is a schematic view showing a method for measuring bending stiffness in Examples and Comparative Examples of the present invention.

[Explanation of symbols]

 Reference Signs List 1 belt 2 woven fabric (A) 3 elastic layer 4 elastic layer 5 surface layer 6 back layer 7 warp 8 weft 9 woven fabric (B) 10 warp 11 weft

Claims (13)

[Claims] 1. A pressure belt for bonding paper, wherein the pressure belt used in a single-sided corrugated cardboard manufacturing apparatus has a structure in which an elastic layer is provided in at least a part of the pressure belt in a thickness direction. 2. The pressure belt for bonding paper according to claim 1, wherein the elastic layer has a core made of a woven fabric made of heat-resistant fibers and is integrated on one or both sides of the core. . 3. The pressure belt for bonding paper according to claim 1, wherein the elastic layer is provided between two layers of fabrics made of heat-resistant fibers. 4. The method according to claim 1, wherein said elastic layer comprises a nonwoven fabric layer.
4. The pressure bonding belt for paper bonding according to any one of claims 1 to 3. 5. The pressure belt for bonding paper according to claim 1, wherein the elastic layer comprises a heat-resistant elastomer layer. 6. The paper bonding pressure belt according to claim 1, wherein the elastic layer is a woven fabric having a three-dimensional woven structure made of heat-resistant fibers. 7. A pressure belt for bonding paper, wherein the belt structure according to claim 1 is impregnated with a heat-resistant and non-adhesive resin or rubber. 8. A pressure for paper bonding, wherein a layer made of a heat-resistant and non-adhesive resin or rubber is provided on the front and back surfaces of the belt product according to any one of claims 1 to 7. belt. 9. A non-woven fabric layer whose main raw material is made of a heat-adhesive fiber is laminated and integrated on one and both sides of an elastic non-woven fabric layer,
5. The paper bonding pressure belt according to claim 4, wherein the non-woven fabric layer is densified and smoothed by hot press treatment to bond and flatten the thermo-adhesive fibers. 10. The elastic layer has a thickness of 100 μm in a thickness direction.
The paper bonding pressure belt according to any one of claims 2 to 9, having the above-described pressure displacement amount. 11. The fiber material of the warp constituting the woven fabric is an organic or inorganic material selected from the group consisting of polyparaphenylene terephthalamide (hereinafter, para-aramid), polyparaphenylene benzobisoxazole (PBO), glass fiber, and carbon fiber. High-strength, high-modulus fibers with a weft of para-aramid, polyarylate, polyetheretherketone (P
The paper bonding according to any one of claims 2 to 10, comprising a heat-resistant fiber selected from the group consisting of EEK), PBO, glass fiber, carbon fiber, polymetaphenylene isophthalamide (hereinafter, meta-aramid), and polyphenylene sulfite (PPS). Pressure belt. 12. The paper adhesive according to claim 7, wherein the heat-resistant and non-adhesive resin / rubber is made of a resin and rubber such as fluorine and silicon, or a mixture thereof. Pressure belt. 13. The heat-adhesive fiber is any one of polyarylate, polyetherimide, polyimide, PPS and its unstretched yarn, and meta-aramid unstretched yarn, and is heat-treated at a temperature equal to or higher than the glass transition point. The pressure belt for bonding paper according to any one of claims 9 to 12, wherein each of the fibers is made of a material that is thermally bonded and stiffened at its entangled point by applying the material, and is made of a material exhibiting rigidity as a whole.