JP2009197896A - Flat belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat belt which is high in a stiffness of finger type joint section, and has an excellent traveling stability. <P>SOLUTION: In an endless flat belt 15, which includes a finger type joint section 12 integrally joined by processing in engaging heat fusion both of ends 11, 11 formed in a saw blade shape, a bending elastic modulus of the finger type joint section 12 is set to be 35 MPa or more. Furthermore, this flat belt 15 consists of five layers structure in which after an intermediate resin layer including thermoplastic elastomer is laminated by extrusion lamination to both surfaces of a fabric layer to which an adhesive is processed in coating or dipping, a surface rubber layer is processed in laminating adhesion to both these surfaces, additionally the bending elastic modulus of the intermediate resin layer is desirable to be 130 MPa or more. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an endless flat belt used for a conveying device or a power transmission device, and more particularly to improving the rigidity of a finger joint portion in the belt width direction.

  As shown in FIG. 4, a flat belt 101 is used to convey the paperboard W in a folder gluer machine 100 that manufactures a paper box by folding and pasting the paperboard W that has been cut into a predetermined shape in advance. The flat belt 101 is used by being twisted at 90 degrees or more in order to bend the paperboard W.

  The flat belt 101 is formed in an endless shape by integrally joining both ends formed in a predetermined shape. As a joining location (namely, joint part), a sky bar joint part, a finger joint part, etc. are mentioned, for example (refer patent document 1).

  As shown in FIG. 5 (a), the sky bar joint portion is formed by laminating both ends of the belt main body portion 102 in an oblique direction and bonding the taper surfaces 103 and 103 with an adhesive, as shown in FIG. 5 (b). It is joined. The sky bar joint portion 104 is generally applied to a flat belt of a nylon film core, and the rigidity in the belt width direction (indicated by the arrow A direction in FIG. 5B) is such that the belt main body portion 102 and the sky bar joint portion 104 have a rigidity. It has the characteristic of not changing significantly.

  However, the sky bar joint portion 104 becomes harder, and the life of the joint portion is shorter than that of the finger joint portion at the same pulley diameter size. Moreover, time is required for joint processing, and skill is required. For this reason, more and more finger joints are employed than skybar joints.

  The finger joint is stamped at both ends of a belt body formed by laminating a woven fabric layer (canvas), an intermediate resin layer made of a thermoplastic elastomer and a surface rubber layer, and meshed with the ends. The thermoplastic elastomer is melted and fused by heat (thermal fusion), and is integrally joined by cooling.

  When applying a flat belt having a finger joint to a special application such as the folder gluer machine 100, the rigidity of the belt body can be improved by improving the rigidity of the woven fabric layer in order to improve the rigidity of the belt. It may be good.

  However, the woven fabric layer is cut in a saw blade shape at the finger joint portion. That is, the finger joint portion is held only by the thermoplastic elastomer, and is easily affected by the physical properties of the thermoplastic elastomer.

For this reason, even if the belt body has rigidity against the force applied in the belt width direction, the finger joint is not sufficiently rigid, and the belt runs on the pulley flange or easily deviates from the flange. There is a problem of doing. This problem remarkably occurs when the belt is twisted and used or when there is a misalignment of the pulley.
Japanese Patent Laid-Open No. 10-29711 (FIGS. 2 and 3)

  An object of the present invention is to provide a flat belt having high finger joint portions and excellent running stability.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a solution means having the following constitution and have completed the present invention.
(1) An endless flat belt having a finger joint portion in which both ends formed in a saw blade shape are meshed and joined together by heat fusion, and the flexural modulus of the finger joint portion is 35 MPa or more. A flat belt characterized by that.
(2) It has a five-layer structure in which an intermediate resin layer containing a thermoplastic elastomer and a surface rubber layer are laminated in this order on both surfaces of the woven fabric layer, and the bending elastic modulus of the intermediate resin layer is 130 MPa or more. (1) The flat belt as described.
(3) The thermoplastic elastomer contained in the intermediate resin layer is a thermoplastic polyurethane elastomer, and the intermediate resin layer includes the thermoplastic polyurethane elastomer, and a thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer. The flat belt according to (1) or (2), comprising a polymer blend obtained by blending
(4) The polymer blend described above, wherein the polymer blend is formed by blending a thermoplastic polyurethane elastomer and a thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer in a weight ratio of 60:40 to 90:10. Flat belt.
(5) The thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer is at least one selected from acrylonitrile-butadiene-styrene copolymer resin, isophthalic acid-modified polybutylene terephthalate resin, and polyamide 12 resin. The flat belt according to 3) or (4).

  According to the present invention, the flexural modulus of the finger joint portion is set to 35 MPa or more. As a result, the finger joints have sufficient rigidity against the force applied in the belt width direction, which suppresses belt deviation due to twisting or pulley misalignment, belt deviation due to riding on the pulley flange, etc. And has an effect that excellent running stability can be exhibited.

  In particular, as described in (2) above, the belt has a five-layer structure in which an intermediate resin layer containing a thermoplastic elastomer and a surface rubber layer are laminated in this order on both sides of the woven fabric layer, When the bending elastic modulus of the layer is 130 MPa or more, the bending elastic modulus of the finger joint portion can be 35 MPa or more.

  When the intermediate resin layer is composed of a polymer blend obtained by blending a thermoplastic polyurethane elastomer and a thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer as in (3), the thermoplastic polyurethane elastomer While maintaining the flexibility and flexibility required of the belt, the rigidity of the intermediate resin layer, that is, the rigidity of the finger joint portion can be increased by the thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer.

  Hereinafter, an embodiment of a flat belt according to the present invention will be described in detail with reference to the drawings. 1A and 1B are schematic perspective views showing finger joint portions of a flat belt according to the present embodiment. FIG. 2 is a diagram showing a broken section taken along line II of FIG.

  As shown in FIG. 1A, the flat belt 15 according to the present embodiment has the end portions 11 and 11 (both ends) of the belt main body 10 punched into a saw blade shape. As shown in FIG. 1B, the endless flat belt has finger joint portions 12 that are joined together and joined together by heat fusion. By employing the finger joint portion 12, the belt can be made endless in a short time and easily.

  Here, it is important that the flexural modulus of the finger joint portion 12 is 35 MPa or more, preferably 45 MPa or more. As a result, the flat belt 15 has sufficient rigidity with respect to the force applied in the belt width direction (the direction indicated by the arrow A in FIG. 1 (b)), and twisting or a pulley error occurs. It is possible to suppress deviation of the belt due to alignment, deviation of the belt due to riding on the pulley flange, and the like, and excellent running stability can be exhibited.

  Although it does not specifically limit as an upper limit of the bending elastic modulus of the finger joint part 12, Usually, it is about 150 MPa or less. In addition, as a bending elastic modulus of the belt main-body part 10, it is good normally that it is about 40-150 MPa. The bending elastic modulus is a value that can be measured according to JIS K 7171.

  As shown in FIG. 2, the flat belt 15 having such a finger joint portion 12 has intermediate resin layers 2 and 2 each containing a thermoplastic elastomer on both surfaces of the woven fabric layer 1, and surface rubber layers 3 and 3, respectively. It consists of a five-layer structure in which are stacked in this order.

  The woven fabric layer 1 is preferably a tensile body and has rigidity. Specifically, the woven fabric layer 1 preferably has a tensile elastic modulus of about 50 to 2000 MPa. The tensile elastic modulus is a value that can be measured according to JIS L 1096.

  Examples of the woven fabric layer 1 include canvas made of polyester fiber, nylon fiber, etc., and examples of the polyester fiber include polyethylene terephthalate fiber (having high rigidity), polybutylene terephthalate fiber, etc. Examples of the fibers include nylon 6 fibers and nylon 66 fibers. In addition, it is preferable that the polyethylene terephthalate fiber which has the said high rigidity has the rigidity whose tensile elastic modulus of the canvas which consists of this fiber is about 1000-2000 Mpa.

  Although the thickness of the woven fabric layer 1 is not specifically limited, Usually, it is preferable that it is about 0.4-1.2 mm.

  The intermediate resin layer 2 has a flexural modulus of 130 MPa or more, preferably 130 to 250 MPa. Thereby, the bending elastic modulus of the finger joint part 12 can be 35 MPa or more.

  Examples of the thermoplastic elastomer included in the intermediate resin layer 2 include a thermoplastic polyurethane elastomer and a polyester elastomer. A thermoplastic polyurethane elastomer is preferable in terms of excellent flexibility and flexibility. In particular, the intermediate resin layer 2 is preferably made of a polymer blend obtained by blending this thermoplastic polyurethane elastomer with a thermoplastic resin having higher rigidity than that of the thermoplastic polyurethane elastomer. Thus, while maintaining the flexibility and flexibility required for the belt by the thermoplastic polyurethane elastomer, the flexural modulus of the intermediate resin layer 2 is set to 130 MPa or more by the thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer. And the bending elastic modulus of the finger joint part 12 can be 35 MPa or more.

  The blend of the thermoplastic polyurethane elastomer and the thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer should be 60:40 to 90:10, preferably 70:30 to 80:20 by weight. .

  On the other hand, if the weight ratio of the thermoplastic polyurethane elastomer is less than 60, the flexibility and flexibility of the flat belt 15 may be reduced. Further, if the weight ratio of the thermoplastic polyurethane elastomer exceeds 90, it is difficult to make the flexural modulus of the intermediate resin layer 2 130 MPa or more, and therefore, the flexural modulus of the finger joint portion 12 may not be 35 MPa or more. There is. Similarly, even when the intermediate resin layer 2 is made of, for example, only a thermoplastic polyurethane elastomer, the bending elastic modulus of the intermediate resin layer 2 cannot be set to 130 MPa or more, and the bending elastic modulus of the finger joint portion 12 cannot be set to 35 MPa or more. There is a fear.

  The thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer has a ratio (E1 / E2) of the bending elastic modulus E1 of the thermoplastic resin and the bending elastic modulus E2 of the thermoplastic polyurethane elastomer of 20 to 200. It is preferable to have a certain degree of rigidity.

  Examples of the thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer include acrylonitrile-butadiene-styrene copolymer resin, isophthalic acid-modified polybutylene terephthalate resin, polyamide 12 resin, polyacetal resin and the like, and in particular, acrylonitrile. -At least one selected from a butadiene-styrene copolymer resin, an isophthalic acid-modified polybutylene terephthalate resin and a polyamide 12 resin is preferable, and these may be used alone or in combination of two or more. Among these, it is preferable that the ratio (E1 / E2) falls within the predetermined numerical range as described above.

  As a method of blending a thermoplastic polyurethane elastomer and a thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer, for example, a method of melt-kneading both of them and biaxial extrusion can be mentioned. It is not limited to. Further, the intermediate resin layer 2 made of such a polymer blend also has an effect of being excellent in adhesion to the woven fabric layer 1 and the surface rubber layer 3. The thickness of the intermediate resin layer 2 is not particularly limited, but is usually preferably about 0.5 to 2.5 mm.

  The resin flow start temperature of the intermediate resin layer 2 is 190 ° C. or lower, preferably 160 to 190 ° C. Thereby, the heat-sealing property of the intermediate resin layer 2 becomes excellent, and the intermediate resin layer 2 can be efficiently flowed to join the end portions 11 and 11 together by heat-sealing.

  The surface rubber layer 3 is formed with perforations which are irregularities regularly arranged so as to have a predetermined coefficient of friction capable of conveying a conveyed product. The surface rubber layer 3 is a rubber layer made of rubber. Examples of the rubber include natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, ethylene propylene rubber, chloroprene rubber, epichlorohydrin rubber, nitrile rubber, acrylic rubber, and acrylonitrile. -Butadiene rubber, urethane rubber, H-NBR (hydrogenated nitrile butadiene rubber) and the like may be mentioned, and these may be used alone or in combination of two or more. Of these exemplified materials, those having oil resistance are preferred.

  The surface rubber layer 3 preferably has a tensile modulus of about 5 to 30 MPa. The tensile elastic modulus is a value obtained by measurement according to JIS K 6251. The thickness of the surface rubber layer 3 is not particularly limited, but is usually preferably about 0.1 to 2 mm.

  Such a flat belt 15 can be manufactured as follows, for example. First, an adhesive is coated or dipped on both surfaces of the woven fabric layer 1 formed into a belt shape. Next, after the intermediate resin layer 2 is laminated on both surfaces of the woven fabric layer 1 subjected to the adhesion treatment by extrusion lamination, the surface rubber layer 3 formed into a belt shape is laminated and bonded to both surfaces to obtain a belt-like flat belt.

  Examples of the adhesive include a one-component or two-component urethane elastic adhesive, a silane-modified polyimide adhesive, and the like. Examples of the method for forming the surface rubber layer 3 into a strip shape include calendering and extrusion molding. When the surface rubber layer 3 is in a sheet shape, the surface rubber layer 3 may be cut out from the sheet into a strip shape. Further, instead of the adhesive, the woven fabric layer 1, the intermediate resin layer 2, and the surface rubber layer 3 may be formed into a belt shape, and these may be laminated and integrated by heating and pressing.

  The belt-like flat belt obtained above is made endless. That is, first, the end portions 11 of the belt main body 10 are punched into a saw blade shape. Next, after the end portions 11 and 11 are meshed with each other, the endless flat belt 15 having the finger joint portion 12 is heated to a temperature at which the intermediate resin layer 2 flows and joined integrally by heat fusion. obtain.

  Such a flat belt 15 is used while twisting a belt such as the folder gluer machine 100 as shown in FIG. 4 because the finger joint portion 12 has sufficient rigidity with respect to the force applied in the belt width direction. In use, it can be suitably used.

  As mentioned above, although preferred embodiment concerning this invention was shown, it cannot be overemphasized that this invention is applicable to what was changed and improved in the range which is not limited to embodiment mentioned above and does not deviate from the summary of this invention. . For example, in the above-described embodiment, the case where the intermediate resin layers 2 and 2 and the surface rubber layers 3 and 3 laminated on both surfaces of the woven fabric layer 1 are configured with the same composition has been described. The composition and thickness may be different.

  Moreover, although the case where the perforation was formed in the surface rubber layer 3 was demonstrated, the surface rubber layer may be comprised by the flat surface.

The flat belt of the present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples. The materials used in the following examples and comparative examples are as follows.
・ NBR (acrylonitrile-butadiene rubber): rubber hardness 70JISA
TPU (thermoplastic polyurethane elastomer): flexural modulus of 50 MPa or less ABS (acrylonitrile-butadiene-styrene copolymer resin): flexural modulus of about 2000 MPa
・ PET (polyethylene terephthalate): A canvas made of PET fiber (a canvas in which the weft is a spun yarn)
Modified PBT (isophthalic acid modified polybutylene terephthalate resin): flexural modulus of about 1400 MPa
Highly rigid PET: A canvas made of highly rigid PET fibers (a canvas in which the weft is made of monofilament fibers)
PA12 (polyamide 12 resin): flexural modulus of about 1000 MPa

The tensile elastic modulus in the surface rubber layer and the woven fabric layer and the bending elastic modulus in the intermediate resin layer containing the thermoplastic elastomer (hereinafter simply referred to as the intermediate resin layer) were measured as follows.
(Tensile modulus)
The surface rubber layer was measured according to JIS K 6251, and the woven fabric layer was measured according to JIS L 1096.
(Flexural modulus)
Measurement was performed in accordance with JIS K 7171.

[Examples 1 to 4 and Comparative Examples 1 and 2]
<Production of flat belt>
The surface rubber layer, the intermediate resin layer, and the woven fabric layer were used in combinations shown in Table 1. That is, first, an adhesive was coated on both surfaces of the woven fabric layer formed into a belt shape. Next, after laminating an intermediate resin layer on both sides of the woven fabric layer subjected to the adhesion treatment by extrusion lamination, a surface rubber layer formed into a belt shape by calender treatment is laminated and adhered to both surfaces, and a belt-like structure having a five-layer structure is formed. A flat belt was produced.

  A two-component curable isocyanate-based urethane adhesive was used as the adhesive. The intermediate resin layers in Examples 1 to 4 are obtained by melt-kneading TPU and one selected from ABS, modified PBT, and PA12 at a weight ratio shown in Table 1, and blending by biaxial extrusion. A polymer blend was used.

The resin flow start temperature of each intermediate resin layer is as shown below.
・ TPU: ABS = 70: 30 is 180 ° C
TPU: modified PBT = 70: 30 is 175 ° C.
-TPU: PA12 = 70: 30 is 180 ° C
・ TPU is 175 ℃

<Evaluation>
Each of the belt-like flat belts obtained above was made endless. That is, first, both ends of the belt main body were punched into a saw blade shape. Next, after meshing the both ends, the intermediate resin layer is heated to a temperature at which the intermediate resin layer flows and joined together by heat fusion, and an endless flat belt having a width of 20 mm and a length of 1000 mm having a finger joint portion is obtained. Obtained. The bending elastic modulus of the belt main body part and finger joint part in each flat belt was measured in the same manner as described above. The results are shown in Table 2.

  Then, a flange test was performed on each endless flat belt. The test methods are shown below, and the results are shown in Table 2.

(Flange test)
As shown in FIGS. 3A and 3B, each endless flat belt is stretched between a driving pulley 50 and a driven pulley 51 arranged horizontally. As shown in FIG. 3A, the driving pulley 50 was misaligned by being arranged with an inclination of 0.96 degrees with respect to the longitudinal direction of the flat belt. A flange 52 is provided on each side of the driving pulley 50 and the driven pulley 51. In this state, the flat belt was run under the following conditions.
Tester: Small running tester Test layout: 2-axis open (see Fig. 3)
Pulley shape: No crown with flange with a diameter of 110 mm Flange shape: Right angle flange Pulley rotation speed: 1740 rpm
Belt speed: Approx. 10 m / sec Traveling time: 168 hours Pulley rotation direction: direction of arrow B in FIG.

Evaluation criteria were set as follows.
○: Drove for 168 hours without abnormality ×: Riding on the flange, the belt deviated from the pulley

  As is apparent from Table 2, the flat belts of Examples 1 to 4 having a flexural modulus of the finger joint portion of 35 MPa or more show good results in the flange test, and are excellent in running stability. Recognize. On the other hand, the flat belt of Comparative Example 1 in which the flexural modulus of the finger joint portion was less than 35 MPa, when the pulley was rotated once, got on the flange and the belt deviated from the pulley. The flat belt of Comparative Example 2 in which the flexural modulus of the finger joint portion is less than 35 MPa and the rigidity of the woven fabric layer is increased (that is, the flat belt with improved rigidity of the belt body portion) is flanged in 2 hours from the start of the test. The belt deviated from the pulley.

(A), (b) is a schematic perspective view which shows the finger joint part of the flat belt concerning one Embodiment of this invention. It is a figure which shows the broken surface of the II line | wire of FIG.1 (b). (A), (b) is a schematic explanatory drawing which shows the flange test in an Example. It is a schematic explanatory drawing which shows a folder gluer machine. (A), (b) is a schematic perspective view which shows a sky bar joint part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Woven fabric layer 2 Intermediate resin layer 3 Surface rubber layer 10 Belt main body 11 End 12 Finger joint 15 Flat belt 100 Folder gluer machine

Claims (5)

  An endless flat belt having a finger joint portion in which both ends formed in a saw blade shape are meshed and joined together by heat fusion, wherein the bending elastic modulus of the finger joint portion is 35 MPa or more. A flat belt.   2. A five-layer structure in which an intermediate resin layer containing a thermoplastic elastomer and a surface rubber layer are laminated in this order on both surfaces of the woven fabric layer, and the flexural modulus of the intermediate resin layer is 130 MPa or more. Flat belt.   The thermoplastic elastomer contained in the intermediate resin layer is a thermoplastic polyurethane elastomer, and the intermediate resin layer is a blend of the thermoplastic polyurethane elastomer and a thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer. The flat belt according to claim 1 or 2, comprising a polymer blend.   4. The flat belt according to claim 3, wherein the polymer blend is obtained by blending a thermoplastic polyurethane elastomer and a thermoplastic resin having higher rigidity than the thermoplastic polyurethane elastomer in a weight ratio of 60:40 to 90:10.   5. The thermoplastic resin having higher rigidity than a thermoplastic polyurethane elastomer is at least one selected from acrylonitrile-butadiene-styrene copolymer resin, isophthalic acid-modified polybutylene terephthalate resin, and polyamide 12 resin. The flat belt described.

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