JPH0848410A - Flat belt for conveyance and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a flat belt for conveyance which is extendable and breakage resistance of which has been improved and manufacture thereof. CONSTITUTION:In a flat belt for conveyance 1, at least one layer of breakage preventing layer 2 is arranged in an elastomer layer 3. In the breakage preventing layer 2, short fiber 5 is dispersed in the elastomer and, in addition, most short fiber 5 is arranged at random in two-axis directions on a plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat belt for transportation,
More specifically, the present invention relates to a flat conveyor belt which is used in a layout having no axial distance adjusting mechanism, is stretchable, and has improved tear resistance, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, a flat belt for transportation which is used in a layout having no axial distance adjusting mechanism needs to be easily expanded and contracted when the belt is attached. It had been. However, a belt made of a single elastic body has a poor tear resistance, and a breakage of the belt is likely to occur during the transportation of paper sheets.
For this reason, in recent years, in order to improve this, a belt using a highly knitted circular knit fabric knitted in a tubular shape by a knitting machine as a reinforcement is used.

Further, recently, a rubber layer in which short fibers are oriented in the circumferential direction of the belt is provided to improve the tearing force in the circumferential direction of the belt, and the sheet is sandwiched and conveyed in multiple directions. A flat belt is disclosed in JP-A-5-221548.

[0004]

However, although the conventional belt made of a single elastic body maintains the homogeneity of the belt, it does not have sufficient tear resistance. In particular, when a small crack is generated on the end surface of the belt for some reason, the propagation of the crack is fast and causes an early belt failure.

On the other hand, in a belt in which a knitted fabric is embedded for the purpose of improving the tear resistance, the propagation of cracks generated at the end face is slowed down, but the knitted fabric is meandering and the stitch density is in the longitudinal or width direction of the belt. Since it was not uniform, it lacked homogeneity and caused a local difference in the elongation of the belt. This is because the belt meanders during transport, comes off the pulley,
Alternatively, it has been a cause of a difference in transport speed. Further, a belt provided with a rubber layer in which short fibers are oriented in the circumferential direction of the belt has a problem of lack of elasticity. Further, a belt can be manufactured by a method in which a liquid raw material is cured in a rotating cylindrical mold, but an inner mold having a diameter smaller than that of the outer mold is inserted into the outer mold, and a belt is formed between the molds. In the case of the molding method, there has been a problem that defects occur in which bubbles remain in the belt. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a flat conveyor belt which is stretchable and has improved tear resistance, and a manufacturing method thereof.

[0006]

That is, a feature of the present invention is that in a flat conveyor belt in which at least one tear-preventing layer is arranged in an elastomer layer, short fibers are dispersed in the elastomer in the tear-preventing layer. In addition, the majority of the short fibers are in the flat conveyor belt which is randomly oriented biaxially on a plane. In the present invention, an elastomer layer is provided above and below the tear-preventing layer, the tear-preventing layer is provided in the surface layer, and the amount of the short fibers added is 1 to 20 parts by weight based on 100 parts by weight of the total elastomer. , The short fiber length is 0.05 to 5 mm, and the fiber diameter is 10
It also includes a flat transport belt having a thickness of -30 μm. In addition, a liquid raw material containing short fibers mixed with short fibers in a liquid prepolymer such as urethane is cast between the inner and outer cylindrical molds vertically arranged, and the liquid prepolymer is crosslinked after rotating the mold. The method also includes a method for manufacturing a flat belt for conveyance, in which a belt sleeve is formed by forming a belt sleeve by cutting the demolded belt sleeve into a predetermined width.

[0007]

In the transport flat belt of the present invention, the majority of the short fibers dispersed in the elastomer in the tear-prevention layer is 2
Random orientation in the axial direction, that is, planar orientation rather than triaxial orientation, each short fiber efficiently reinforces the tensile force in the belt length direction and also improves tear resistance. Since they are dispersed independently without being entangled with each other, the stretchability is not impaired, and the durability against tearing is excellent even when the belt is running under stretching. Further, since most of the short fibers are randomly oriented in the biaxial direction and are independently dispersed, the amount of the short fibers added can be reduced and good belt stretchability can be maintained. Further, according to the production method of the present invention, it is possible to form a tear preventing layer in which biaxially oriented short fibers are biaxially oriented in a belt, and a belt with less defects due to bubbles in the elastomer can be obtained. .

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a transporting flat belt according to the present invention, FIG. 2 is a cross-sectional perspective view of a tear-preventing layer, FIG. 3 is a cross-sectional view of another transporting flat belt according to the present invention, and FIG. FIG. 5 is a cross-sectional view of yet another transporting flat belt, and FIG. 5 is a cross-sectional view of a transporting flat belt that is still another embodiment of the present invention.

In the figure, in a flat belt 1 for conveyance, a tear prevention layer 2 and upper and lower elastomer layers 3 are formed. Each of the elastomer layers 3 is made of an elastomer alone, and a conveyance layer 6 in contact with a conveyed object and a drive layer in contact with a pulley. 7
And form. On the other hand, in the tear prevention layer 2, the majority of the short fibers 5 dispersed in the elastomer are randomly oriented in a biaxial direction on a plane, that is, not a triaxial orientation but a plane orientation. Each short fiber 5 efficiently reinforces the tensile force in the belt length direction and improves the tear resistance. Furthermore, since the short fibers 5 are dispersed independently without being entangled with each other, the belt has sufficient elasticity.
The tear preventing layer 2 may be one layer or more.

Thus, the layer in which the majority of the short fibers 5 are randomly oriented in the plane in the biaxial direction in the elastomer forms the tear preventing layer 2 and serves as the belt reinforcing layer. Therefore, the thickness of the tear prevention layer 2 is 10 to 90%, preferably 20 to 60% of the total thickness of the belt 1.
The amount of the short fibers 5 dispersed in the layer 2 is 1 to 20% by weight based on 100 parts by weight of the total elastomer.
If it is less than 1% by weight, the reinforcing effect of the short fibers is reduced and tearing tends to occur, and this belt is manufactured by centrifugal casting as described later, but the amount of the short fibers added exceeds 20%. Therefore, there is a problem that it cannot be formed by centrifugal casting, the short fibers are entangled with each other and are not dispersed independently, and the dispersion state becomes non-uniform and the stretchability of the belt is impaired.

The short fibers 5 are nylon, polyester, aramid, cotton, glass, etc. The length of these short fibers is 0.05 to 5 mm and the fiber diameter is 10 to 30 μm, and the most preferable one is It is called flock. If the short fiber length is less than 0.05 mm,
The effect of randomly orienting biaxially on a plane disappears, and the effect of preventing the belt from tearing becomes poor. On the other hand, when the fiber length is longer than 5 mm, the short fibers are entangled with each other and cannot be dispersed independently, so that the dispersed state becomes nonuniform and the stretchability of the belt is impaired.

The flat conveyor belt 1 shown in FIG.
Is formed of a tear-preventing layer 2 randomly oriented in a biaxial direction on a plane and independently dispersed, and an elastomer layer 3 made of an elastomer alone. In this belt 1, warpage tends to occur on the elastomer layer 3 side, but it is expandable and contractible and tear resistance is improved.

The flat conveyor belt 1 shown in FIG.
Most of the fibers are randomly oriented in a biaxial direction on a plane and independently dispersed, and a tear preventing layer 2 and short fibers 5 having the same structure are provided.
And the elastomer layer 3 containing. However, when the amount of the short fibers 5 dispersed in the tear prevention layer 2 is larger than that in the elastomer layer 3, the dispersion density of the short fibers changes from the outer surface 9 of the tear prevention layer 2 to the elastomer layer 3. Gradually decreases toward the inner surface 10 of the.

A high coefficient of friction is required for the transporting flat belt 1 when slipping cannot be performed depending on the transported material and the transportation method. In addition, when a certain amount of slip is required to prevent damage to the conveyed product when it is taken in, a relatively low coefficient of friction is required. In the belt 1 of the present invention, a high friction coefficient can be obtained by forming a layer containing no short fibers in the transport layer 6, and a low friction coefficient can be obtained by providing a layer containing short fibers on the surface. Obtainable. Further, in order to enable stable conveyance, the warp in the belt width direction can be reduced by disposing the elastomer layer 3 composed of a single elastomer vertically symmetrical with respect to the tear prevention layer 2.

Further, in order to obtain a belt having a small elongation in the longitudinal direction of the belt, as shown in FIG. 5, a belt having a cord having a high strength and a low elongation rope tensile body embedded in a spiral shape is provided. Is also possible. Elastomers used in the present invention include thermosetting liquid rubbers such as polyurethane, silicone, various hydrocarbon synthetic rubbers such as carboxyl group-terminated polybutadiene, and the like, and polyurethane is most preferable.

The polyurethane is a prepolymer having a polyisocyanate group at the terminal obtained by reacting an active hydrogen terminated linear polymer with a molar excess of organic polyisocyanate, glycols, amines, hydrazides, or amino. It is a highly elastic polymer obtained by reacting alcohols and the like.

As the above-mentioned active hydrogen terminated linear polymer,
It is appropriately selected from polyether polyols, polyester polyols, polylactone polyols, polyether ester polyols, and polyhydrocarbon polyols having a molecular weight of 250 to 5000, which have a completely linear or slightly branched molecular structure, but the reactivity, In terms of workability, polyether polyol is preferable.

The organic polyisocyanate is 2.4
-Toluene diisocyanate, 2.6-toluene diisocyanate, 1.5-naphthalene diisocyanate, hexamethylene diisocyanate, 4.4'-diphenylmethane diisocyanate (pure MDI), polymeric MDI (crude MDI) and the like, usually 4,4 '
-A liquid obtained by modifying diphenylmethane diisocyanate (MDI) is used.

(Evaluation of Transporting Flat Belt) Next, the transporting flat belt of the present invention was manufactured and its characteristics were evaluated. The prototype belt has 0.2-0.7 mm long nylon short fibers with a diameter of 25 μm that are randomly oriented biaxially on a plane and are independently dispersed on top of a 0.2 mm thick tear prevention layer. Has an elastomer layer having a thickness of 0.3 mm and an elastomer layer having a thickness of 0.5 mm at the bottom, and has a width of 10 mm,
It has an inner peripheral length of 310 mm.

The method for manufacturing the above belt is as follows. First, the outer mold having a cylindrical inner diameter of 100.6 mm is 100
After installing in a centrifugal casting machine placed in a high temperature tank adjusted to ° C, a urethane stock solution containing no short fibers (100 parts by weight of prepolymer, 4,4'-diamino-3,3'dichlorodiphenylmethane 8 parts by weight of a certain curing agent, 40 parts by weight of plasticizer, 0.5 parts by weight of catalyst) were cast into the outer mold and the centrifugal casting machine was rotated at a rotation speed of 4500 for 5 minutes to semi-crosslink the outer mold. A 0.5 mm thick elastomer layer was formed.

Further, with respect to 100 parts by weight of the above-mentioned urethane undiluted solution, a urethane undiluted solution containing 5% by weight of nylon short fibers having a length of 0.2 to 0.7 mm and a diameter of 25 μm is cast into the outer mold and centrifugally injected. The mold machine was rotated at 4500 rpm for 12 minutes. At this time, the short fibers having a larger specific gravity than the undiluted urethane solution are gathered to the outside by a centrifugal force and contain a large amount of short fibers, the majority of which are randomly oriented biaxially on a plane and are independently dispersed to form a crosslinked thick A tear prevention layer having a thickness of 0.2 mm was formed. At the same time, a 0.5 mm thick elastomer layer containing almost no short fibers was formed on the inner peripheral surface. The tear-prevention layer and the elastomer layer containing almost no short fibers are integrally molded without separation.

The cross-linked sleeve having a thickness of 1.2 mm thus formed is ground by a grinder until the thickness becomes 1.0 mm, and then cut by a cutter to obtain a conveying flat belt having a width of 10 mm. It was

In Comparative Example 1, a flat conveyor belt having a total thickness of 1.0 mm and a width of 10 mm and made of a urethane elastomer layer having no tear preventing layer was used. In addition, Comparative Example 2
Then, a flat belt for conveyance having a total thickness of 1.0 mm and a width of 10 mm in which a circular knitted cloth made of polyester having a thickness of about 0.3 mm is laminated almost at the center of the urethane elastomer layer was used.

Table 1 shows the results of measuring the tearing force, the durability against tearing, the fluctuation in rotation, and the amount of lateral shake of the belt during running of the above-prepared belt and the belt of the comparative example by the following methods.

1. Tear force of belt This measurement was performed based on JIS K6301.

2. Durability against tearing Attach a test belt with a notch with a width of 1 mm at its side end at an elongation rate of 10% to a driven shaft having a flat pulley with a diameter of 20 mm and a driven shaft having a flat pulley of the same diameter, and keep it at room temperature. The state of the belt after running for 100 hours without rotating the driven pulley at 2000 rpm and the driven shaft was observed.

3. Rotational fluctuation In this test method, the test belt was attached to a driven shaft having a flat pulley having the same diameter as the drive shaft having a flat pulley having a diameter of 20 mm at an elongation rate of 10%, and the rotational speed of the drive pulley was 60 rpm at the room temperature and the driven belt was driven. The vehicle was run without an axial load, and the rotational fluctuation of the driven shaft was measured by a rotary encoder attached to the driven shaft. A flywheel having a sufficient inertial weight was attached to the drive shaft in order to eliminate rotation fluctuation due to the motor.

4. Amount of lateral belt runout during running In this test method, the test belt was attached to a driven shaft having a flat pulley having a diameter of 20 mm and a driven shaft having a flat pulley having the same diameter at an elongation rate of 10%, and the test pulley The vehicle was run at a rotation speed of 500 rpm and no driven shaft load, and the swing width was measured with an infrared type lateral shake amount measuring device.

[0029]

[Table 1]

As a result, the flat belt for conveyance of the present invention has a tearing force which is 80% greater than that of the belt having no tear preventing layer, and also compared with the conventional belt using the knitted cloth. It has a large tearing power of 20%. The durability test under belt extension also shows that the belt of the present invention is superior to the conventional belt. Further, it is found that the rotation fluctuation test of the belt according to the present invention and the lateral vibration of the belt during running are equivalent to those of the belt having no tear preventing layer and are superior to those of the conventional belt.

Next, in the flat belt for conveyance of the present invention, for example, a mold used for manufacturing a belt in which a core wire is embedded in the belt is performed by inserting an inner mold into an outer mold. In that case, bubbles in the elastomer are difficult to escape, and defects including bubbles are likely to occur. Therefore, by using the method as claimed in claims 7 to 11, it is possible to satisfactorily defoam and reduce defects. A specific example of the method for producing a flat transport belt in which a biaxially oriented short fiber layer, which is a tear prevention layer, is present in the intermediate portion of the flat belt shown in FIG. Will be described below. Of course, the manufacturing method of the present invention is not limited to the examples described below.

FIG. 6, FIG. 7, FIG. 8 and FIG. 9 are sectional views showing an embodiment relating to the manufacturing method of the present invention. In order to improve the disappearance of air bubbles, 40 parts by weight of a plasticizer is added to 100 parts by weight of a liquid prepolymer of urethane as a raw material L for forming the transport layer 6 on the belt surface, and the mixture is stirred and kept at 60 ° C. The mixture is preheated and then degassed. 0.5 part by weight of a catalyst is added to 8 parts by weight of a curing agent, and the temperature is kept at 110 ° C.

Liquid prepolymer 1 of urethane as a raw material R for forming the tear prevention layer 2 and the drive layer 7 inside the belt.
Nylon short fibers (fiber length 0.2 to
0.7 mm fiber diameter φ25 μm) 5 parts by weight, and further 40 parts by weight of a plasticizer are added and stirred. This is 60 °
Keep warm at C. In order to improve the disappearance of bubbles, the mixture is preheated and then defoamed. 0.5 part by weight of a catalyst is added to 8 parts by weight of a curing agent and the temperature is kept at 110 ° C.

A bottom mold 13 on a centrifugal molding machine adjusted to 100 ° C. by inserting a cylindrical inner mold 11 having a diameter of about 100 mm into an outer mold 12 and placing this mold in a constant temperature bath. Then, the upper mold 14 is placed on the inner mold 11 and the outer mold 12 and fixed to form a mold. As shown in FIG. 6, the raw material L for the drive layer 6 on the surface of the belt prepared in advance is injected into the inner mold 11. The injection amount at this time needs to be adjusted in order to make the thickness of the drive layer 6 on the surface of the belt a predetermined thickness.

As shown in FIG. 7, about 4500 rpm (about 1
The raw material L is cast into the mold from the gate 15 by rotating the mold with a centrifugal force of 0000 N), and the outer transfer layer 6 is semi-crosslinked for defoaming and curing. As shown in FIG. 8, when the semi-crosslinking of the transport layer 6 is completed, the rotation of the mold is stopped. Next, as shown in FIG. 9, the tear preventing layer 2 and the raw material R for forming the drive layer 7 on the inner side of the belt are poured into the mold to rotate the mold at a speed of about 4500 rpm (a centrifugal force of about 10000 N is applied) to about 30. Gradually raise over a period of seconds. Crosslinking is performed for about 12 minutes when the rotation is constant. After completion of the crosslinking, the mold is taken out of the molding machine and the molded product is released from the mold to form a belt sleeve having the tear prevention layer 2 at the intermediate portion of the belt, and the belt can be obtained by cutting the belt into a predetermined width.

In the case of the flat belt for conveyance shown in FIG. 3, which has a layer of short fibers which is the tear preventing layer 2 on the surface of the belt and which is oriented biaxially, a raw material R containing short fibers is used from the beginning. It can be manufactured by pouring a little more than to form the entire belt. In the above-described manufacturing method, when the raw material R containing short fibers is cast into the mold, if the rotation speed of the mold is too high, the short fibers are centrifuged near the gate 15 existing in the lower part of the mold. Since the force will stick to the inner wall side of the outer mold 12 and the tear prevention layer 2 having an average thickness cannot be formed on the entire belt sleeve, when the raw material containing short fibers is cast, the mold is rotated. Is stopped or the number of rotations is lowered to cast the raw material R. By doing so, the short fibers are substantially evenly dispersed up to the upper portion of the cylindrical mold, and if the rotation is increased thereafter, the tear prevention layer 2 can also be formed to have a uniform thickness.

With the rotation of the mold stopped, the raw material L is poured into the inner mold to gradually increase the rotation of the mold so that the mold is cast between the inner and outer molds and the short fibers are molded into the mold. You can disperse up to the top. Alternatively, the rotation of the mold may be kept low and the raw material L may be injected and cast, and then the rotation may be gradually increased. The rotation speed at the time of injecting the raw material needs to be set so that the centrifugal force applied to the raw material is 1000 N or less. The rotation speed for reducing the centrifugal force to 1000 N or less depends on the diameter of the mold, and the centrifugal force: F [N],
Mold radius: r [m], mold rotation speed per minute: W [r
pm], the rotation speed is calculated by the following formula W = 30 / π (F / r) ^1/2 . For example, for a die of φ100 mm, the speed is set to about 1350 rpm or less.

In addition, according to this manufacturing method, a belt having a layer in which short fibers are biaxially oriented can be obtained, and defects due to air bubbles in the belt hardly occur. It is because the bubbles in the raw material move inward by the centrifugal force and disappear, but the inner mold 1
This is because the bubbles existing near the surface of 1 can escape from the upper gate 16. The manufacturing process for the case where the tear prevention layer 2 is provided on the surface of the belt and the case where the tear prevention layer 2 is provided at the intermediate portion of the belt have been described above. 43
By setting the rotation speed to 0 rpm and 100 N), it is possible to manufacture a belt in which the boundary between the tear preventing layer 2 and the drive layer 7 is unclear as shown in FIG.

When manufacturing a belt in which the core wire S is embedded as shown in FIG. 5, the rope which becomes the core wire S is attached to the inner mold 1.
Need to wrap around 1. The manufacturing process will be described in detail. To 100 parts by weight of the prepolymer, 5 parts by weight of nylon short fibers (fiber length, 0.7, fiber diameter φ25 μm) were added, and 40 parts by weight of a plasticizer was further added and stirred. I do. This is kept at a temperature of 60 ° C. In order to improve the disappearance of bubbles, the mixture is deheated after being preheated. Add 0.5 parts by weight of catalyst to 8 parts by weight of curing agent at 110 ° C.
Keep it warm. After the polyester core wire S is spirally wound around the inner mold 11 having a diameter of about 100 mm, the inner mold 11 is inserted into the outer mold 12, and this mold is placed on the bottom mold 1 on the centrifugal molding machine.
4 and then the upper die 13 is placed and fixed. 9
The temperature is raised to 0 ° C., and the prepolymer in which the preheated degassed short fibers and the plasticizer are stirred is further mixed with a curing agent and stirred for 30 seconds, and the mixture is poured into the inner mold 11. Rotate the mold 4
The raw material R is gradually increased to 500 rpm (to generate a centrifugal force of 10000 N) over 30 seconds.
Is cast into the mold.

In this state, crosslinking was carried out for 15 minutes. In the case of a raw material, since the time from the start of stirring to the completion of filling can be treated in a short time, the amount of catalyst added can be made larger than usual. Therefore, the crosslinking time is shortened. Further, after the completion of crosslinking, the mold can be removed from the molding machine, and the inner mold 11 can be separated to obtain a cored belt having the tear preventing layer 2 on the surface.

A tear preventing layer 2 having a core wire S
The same applies to the method of manufacturing a flat belt for transportation having the intermediate portion of the belt, and as in the method of manufacturing the belt of FIG. 1, the raw material L of only the elastomer for the transportation layer 6 is first cast to be in a semi-crosslinked state. It can be manufactured by adding the step of putting to the manufacturing method of the belt shown in FIG.

Similarly, in the method of manufacturing a belt having a core wire, variations in the density of short fibers in the belt sleeve are not so great. At the time when the raw material is filled in the gap between the inner mold and the outer mold, the short fibers having a larger specific gravity than the liquid prepolymer are not subjected to centrifugal force enough to cause centrifugal separation. By further increasing the rotation speed, the short fibers are centrifugally separated by the centrifugal force and the short fibers are concentrated on the outer surface, and the short fiber density does not significantly differ between the upper and lower parts of the mold.

[0043]

As described above, in the transport flat belt of the present invention, the majority of the short fibers dispersed in the elastomer in the tear-prevention layer are randomly oriented in the biaxial direction, that is, not oriented in the triaxial direction but planarly oriented. Since each short fiber is efficiently reinforced against tensile force in the belt length direction to improve tear resistance, each short fiber is dispersed independently without being entangled with each other, and the addition amount is small. Therefore, the stretchability is not impaired, and therefore the durability is good, and there is little fluctuation in rotation and lateral vibration of the belt, which is effective. Further, according to the production method of the present invention, the tear preventing layer in which the short fibers are randomly oriented in the biaxial direction can be easily formed and formed at a desired position of the belt, and a belt having few defects such as bubbles can be obtained. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a transporting flat belt according to the present invention.

FIG. 2 is a sectional perspective view of a tear preventing layer.

FIG. 3 is a sectional view of another conveyance flat belt according to the present invention.

FIG. 4 is a cross-sectional view of still another conveying flat belt according to the present invention.

FIG. 5 is a cross-sectional view of still another conveying flat belt according to the present invention.

FIG. 6 is a cross-sectional view showing a step in a method for manufacturing the flat conveyor belt shown in FIG.

FIG. 7 is a cross-sectional view showing a step in a method for manufacturing the transport flat belt shown in FIG.

FIG. 8 is a cross-sectional view showing a step of a method for manufacturing the flat belt for conveyance shown in FIG.

FIG. 9 is a cross-sectional view showing a step of a method for manufacturing the flat conveyor belt shown in FIG.

[Explanation of symbols]

 1 Flat Belt for Transport 2 Tear Prevention Layer 3 Elastomer Layer 5 Short Fiber 6 Transport Layer 7 Drive Layer 11 Inner Mold 12 Outer Mold 13 Upper Mold 14 Bottom Mold L Raw Material for Transport Surface R Tear Prevention Layer and Drive Surface Raw material for use S core

Front page continued (72) Inventor Shusuke Takashima 4-1-2-1, Hamazoe-dori, Nagata-ku, Kobe Mitsuboshi Belt Co., Ltd. (72) Inventor Yasunori Matsuo 4-1-2-1, Hamazoe-dori, Nagata-ku, Kobe Mitsuboshi Belt Co., Ltd. (72) Inventor Hiroshi Okawa 4-1-2-1, Hamazoe-dori, Nagata-ku, Kobe Mitsuboshi Belt Co., Ltd.

Claims (11)

[Claims] 1. A transporting flat belt in which at least one tear-prevention layer is arranged in an elastomer layer, wherein short fibers are dispersed in the elastomer in the tear-prevention layer, and most of the short fibers are biaxial on a plane. A flat belt for conveyance, which is randomly oriented in the direction. 2. The flat conveyor belt according to claim 1, wherein the majority of the short fibers are dispersed independently. 3. The transport flat belt according to claim 1, wherein elastomer layers are disposed above and below the tear prevention layer. 4. The flat conveyor belt according to claim 1, wherein the tear preventing layer is provided on the surface layer. 5. The total amount of the short fibers added is 100 elastomers.
1 to 20 parts by weight with respect to parts by weight.
Or the flat belt for conveyance according to item 4. 6. The short fiber has a length of 0.05 to 5 mm and a fiber diameter of 10 to 30 μm.
Flat belt for transportation as described. 7. A cylindrical outer mold in which an inner mold having a smaller diameter than the outer mold is inserted, and the liquid prepolymer is provided with a short fiber in a rotary device so that its axis is substantially vertical. The short fiber biaxially oriented in the liquid raw material by pouring the liquid raw material containing short fibers mixed with the above into the molds that are stopped or rotating at a relatively low speed and increasing the rotational speed of both molds. Flat belt for transportation, characterized in that a belt having a tear-preventing layer is obtained by cross-linking a liquid raw material in a state of forming a layer to form a cylindrical sleeve shape, and taking out from a mold and then cutting it into a predetermined width. Manufacturing method. 8. The mold according to claim 7, wherein the liquid raw material containing the short fibers in which the liquid prepolymer is mixed with the short fibers is cast into the mold through a casting gate arranged at the bottom of both molds installed in a substantially vertical direction. Manufacturing method of flat belt for transportation. 9. The transport flat belt according to claim 7, wherein the number of rotations of the mold when casting the liquid raw material containing the short fibers is set so that the centrifugal force applied to the liquid raw material is 1000 N or less. Manufacturing method. 10. Prior to the step of casting the mixture of the liquid raw material containing short fibers and the curing agent, the mixture of the liquid raw material containing no short fibers and the curing agent is cast into the mold, and then placed in the mold. The method for manufacturing a flat belt for transportation according to claim 7, wherein a semi-crosslinked elastomer layer is formed. 11. The method of manufacturing a flat belt for conveyance according to claim 7, wherein a rope tensile member having a high strength and a low elongation is wound around the surface of the inner mold in a spiral shape.