JPH02152807A - Conveyer belt - Google Patents

Abstract

PURPOSE:To reduce the weight and improve the durability and to reduce elongation and improve rigidity by providing plural fiber reinforced layers where a flat monofilament cord which is untwisted and has a designated ratio of width to thickness is used in warp and weft. CONSTITUTION:A monofilament 20 which is flat in section and has the ratio W/H of width W to thickness H ranged from 2.0 to 4.0 is used in warp and weft without twisting, and rubberized to form a fiber reinforced layer. As the monofilament 20, 6-nylon, 66-nylon or the like is used. A conveyer belt 10 is formed by the fiber reinforced layers 1-4. By this arrangement, the conveyer belt can be reduced in size, improved in durability, reduced in elongation and improve in rigidity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is lightweight, has excellent durability, exhibits little growth and elongation due to use, and has excellent rigidity. This invention relates to a conveyor belt suitable for transporting articles.

[Conventional technology]

-a, the conveyor belt is constructed as shown in FIG. In FIG. 1, a plurality of fiber reinforcement layers 1, 2, 3.
' 4 are laminated, and the surface is a cover rubber layer lO
covered with. The fiber reinforcing layers 1, 2, and 3.4 are each made of woven fibers (plain weave, twill weave, etc.) and rubberized, or fiber cords made of a plurality of fiber filaments are embedded in rubber to form a sheet. This is what I did.

Conventionally, fibers of several deniers were used as fibers for such fiber reinforcement layers.
So-called multifilament fibers, which consist of many filaments with a thickness of several seven deniers, are twisted in a cord shape and used for warp and weft yarns.

[Problem that the invention seeks to solve]

However, due to twisting, the diameter of the cord becomes thicker, so the coated rubber layer in which the cord is embedded must necessarily be thicker, and as a result of the increased amount of rubber, the weight of the conveyor belt increases. However, this method has the disadvantage of increasing the energy cost required to operate the conveyor belt.

Furthermore, the twisting reduces the initial modulus of the cord, resulting in increased growth (elongation) when a conveyor belt is used. Furthermore, there is also the problem that adding twist increases material costs.

Note that growth due to use here refers to the fact that the conveyor belt stretches and slackens due to use, and rigidity refers to the rigidity with which the conveyor belt holds the load as a conveyor belt for transporting objects.

In order to solve these problems, a method can be considered in which a so-called multifilament fiber consisting of a large number of filaments with a thickness of several deniers to several tens of deniers is not twisted and is used as a non-twisted cord. However, when untwisted,
As a result of the reduced convergence of the cord, the adhesion with rubber and bending fatigue resistance are significantly reduced, resulting in a significant deterioration in the durability of the conveyor belt.

Also to reduce the weight of conveyor belt.

If the thickness of the coat rubber is simply reduced, shear strain between the fiber-reinforced layers will increase, and the adhesive force between the fiber-reinforced layers will also decrease, resulting in deterioration of the durability of the conveyor belt.

Therefore, the ratio of the thickness of the fiber reinforcing layer to the thickness of the coated rubber layer is usually in the range of 0.4 to 0.8.

[Purpose of the invention]

This invention was devised by focusing on the problems of the conventional art, and aims to provide a conveyor belt that is lightweight, has excellent durability, has little growth due to use, and has excellent rigidity. .

[Means to solve the problem]

In order to achieve the above object, the present invention provides a conveyor held comprising at least one fiber reinforcing layer, in which the reinforcing layer includes warp yarns, weft yarns, or both warp and weft yarns having a substantially untwisted flat cross section. It is composed of a monofilament cord having a shape, and the ratio of width (W) to thickness (H) (W/H) of the monofilament cord is 2.0 to 4.0.
The gist is that it is within the range of

The monofilament cord 20 having a flat cross-sectional shape used in the present invention is a cord 20 consisting of one filament having an elliptical cross-sectional shape, as shown in FIG. 2(a), for example. The fiber cord 30 is significantly different in shape from the conventional fiber cord 30, which is made by twisting so-called multifilament fibers made of a large number of filaments having a thin circular cross-sectional shape.

Here, the material of the monofilament cord is not particularly limited, but nylon 6, nylon 66, polyester, etc. are used, and nylon is more preferable from the viewpoint of adhesion to rubber and bending fatigue resistance.

Further, the thickness of the monofilament cord is not particularly limited, but a range of 500 denier to 10,000 denier is preferable in terms of bending hardness, durability, and weavability of the cord.

Furthermore, the monofilament cord must be used substantially untwisted. When twisted, surface distortion occurs in the monofilament cord, resulting in a significant decrease in durability and strength.

The monofilament cord has a width (W) to thickness (H) ratio (W/H) of 2.0 to 4.0, preferably 2.0 to 4.0.
It is in the range of 5 to 3.5.

If the above range is less than 2.0, the thickness of the coat becomes too thick and the rubber layer in which the cord is embedded also becomes thick.2
Not only does this increase the weight of the conveyor heald, but in the case of conveyor belts that are subject to bending fatigue at the pulleys, surface distortion of the cords also increases, reducing the durability of the conveyor belt.

On the other hand, if it is 4.0 or more, the width of the cord becomes wider and the number of cords that can be driven into a given width of light decreases, so the required strength may not be obtained, or the number of cords laminated to obtain the required strength may be reduced. This would significantly impede productivity.

Furthermore, when an 8-wire monofilament cord of greater than 4.0 is used for the weft, the lateral rigidity of the conveyor belt is reduced.

It is preferable that the monofilament cord has a strength of 7.0 g/d or more and an initial modulus of 45 g/dlu or more. If the strength is less than 7.0 g/d, it is necessary to increase the number of cords inserted and the number of layers laminated, which is not preferable in terms of weight reduction and productivity. Initial modulus is 45 g/
If it is less than d, not only will slack occur when an article is placed on the conveyor belt (but also growth due to running will increase).

Furthermore, when embedding the monofilament cord in rubber, it is necessary to embed the cord in the thickness direction, that is, in parallel with the short axis direction of the cross section of the cord and the thickness direction of the coated rubber. If the long axis direction of the cord cross section is buried parallel to the thickness direction of the coated rubber, not only will the thickness of the coated rubber not be reduced, but also the bending fatigue resistance will be reduced and the durability of the conveyor belt will be deteriorated.

After the monofilament cord is woven, it is coated with an adhesive and dry heat treated. At this time, 1/1 of the conveyor belt
It is preferable that the elongation rate under a 10% guaranteed strength load is 4.0% or less, and the dry heat shrinkage rate at 150° C. is 6.0% or less.

If the elongation rate of the adhesive-treated fabric exceeds 4.0%, the initial modulus of the fiber reinforcing layer will be too low, which will not only cause slack when the article is placed on the conveyor belt, but also thick growth due to running. .

Furthermore, if the dry heat shrinkage rate at 150°C exceeds 6.0%, dimensional changes during conveyor belt manufacturing will become large.
The initial modulus of the fiber reinforcement layer decreases.

Further, the coat rubber (covering rubber) in which the fiber reinforcing layer is embedded is not particularly limited in the present invention, and NR, SBR, CR, NBR, EPR, etc. can be used as appropriate depending on the purpose.

Further, the type and amount of the vulcanization accelerator and anti-aging agent added when vulcanizing the coated rubber are not particularly limited.

Examples of this invention are shown below.

The following conveyor belts were manufactured and evaluated for durability, growth, weight, and rigidity.

The results of this Example 1 are shown in Table 1 below.

*Conveyor belt A (present invention) Strength 8. 6g/d, initial modulus 51g/d 66
Made of nylon, width (W) 1.0 mm, thickness (H) 0.
A monofilament cord having a flat oval shape of 36 mm, a ratio (W/H) of 2.8, and 3000 denier (D) was used as the warp yarn. The twist is O.

In addition, the weft yarn was a normal multifilament fiber (number of filaments: 2IO, filament thickness: 6D) of 66 nylon 1260D/1 with a strength of 9.5 g/d and an initial modulus of 45 g/d, twisted 15 times per 10 cm. The added one was used. Fabrics were made using these cords, coated with adhesive, dried, and then placed under a tension of 0.3 g/d.

A bonded fabric having the following structure was obtained by heat treatment at 220°C.

The elongation rate of this fabric under a 1/10 guaranteed strong load is 1
．． 5%, and the dry heat shrinkage rate at 150'c is 2.3
%Met.

Also, the tensile strength of this fabric is l 84kg f/1cm
The thickness was 0.60 mm.

Structure of woven fabric: 40 x 35 (15 cm) Next, on both sides of this woven fabric, the ratio of the thickness of the woven fabric to the thickness of the rubber layer I/back is 0.
．． 6, that is, the thickness after coating is 1. Rubber was coated to a thickness of 0 mm. Furthermore, four layers of each of these were laminated, and the surface thereof was further covered with a cover rubber layer and then vulcanized to produce a conveyor belt.

*Conveyor belt B (comparative example) Made of 66 nylon with a strength of 8.6 g/d and an initial modulus of 51 g/d, the width (W) is 0.75 mm and the thickness (H) is 0.
A monofilament cord having a flat elliptical shape of 50 mm, a ratio (W/H) of 1.5, and 3000 denier (D) was used as the warp yarn. The twist is O.

In addition, the weft yarn has a strength of 9.5 g/d and an initial modulus of 4.
A normal multifilament fiber (number of filaments: 210, filament thickness: 6D) of 5 g/d 66 nylon 1260D/1 twisted 15 times per 10 cm was used.

After making a fabric using these cords, applying adhesive and drying, 0.3. A bonded fabric having the following structure was obtained by heat treatment at 220° C. under a tension of g/d. 1/l O of this fabric
The elongation rate under the guaranteed strong load is 1.5%, which is 15
The dry heat shrinkage rate at 0°C was 2.3%.

The tensile strength of this fabric was 184 kgf/1 cm, and the thickness was 0.74 mm.

Textile structure Warp yarn Weft yarn 3000D/1 x 1260D/1 40 x 35 (15cm) Next, the ratio of the thickness of the fabric of conveyor belt A to the thickness after rubber coating (
0,6) so that the ratio is the same, that is, the thickness after coating is 1
．． Rubber was coated to a thickness of 2 mm. Furthermore, four layers of each of these were laminated, and the surface thereof was further covered with a cover rubber layer and then vulcanized to produce a conveyor belt.

*Conveyor belt C (comparative example) Made of 66 nylon with strength 8.6 g/d and initial modulus 51 g/d, width (W) 1.30 mm, thickness (H) 0.
28mm, the ratio < W / H) is 4.5 and 3000
A monofilament cord having a flat elliptical shape with a denier (D>) was used as the warp yarn.The twist was O.

In addition, the weft yarn has a dual strength of 9.5 g/d and an initial modulus of 4.
A normal multifilament fiber (number of filaments: 210, filament thickness: 6D) of 5 g/d of 66 nylon 1260D/1 twisted 15 times per IQcm was used.

An attempt was made to use these cords to create a fabric with strength equivalent to that of conveyor belts A and B, but because the width of the monofilament cord was 1.3 mm, it was not possible to insert the required number of warp yarns.

Therefore, a comparative evaluation was not possible.

*Conveyor belt D (conventional example) Strength 9.5 g/d, initial modulus 45 g/d 66
A normal 1260D/2 multifilament fiber made of nylon (number of filaments: 210, filament thickness: 6D) twisted 13 times per locm was used as the warp yarn.

In addition, the weft yarn has a strength of 9.5 g/d and an initial modulus of 4.
A normal multifilament fiber (number of filaments: 2 IO, filament thickness: 6 D) of 5 g/d nylon 66 and 1260 D/l twisted 15 times per 10 cm was used.

Using these cords, fabrics are made to have the same strength as conveyor belts A and B, and after applying adhesive and drying,
Heat treatment was performed at 220° C. under a tension of 0.3 g/d to obtain an adhesive-treated fabric having the following structure.

The elongation rate of this fabric under a 1/10 guaranteed strong load is 2
．． 4%, and the dry heat shrinkage rate at 150℃ is 2.7%.
Met.

The tensile strength of this fabric was 186 kgf/1 cm, and the thickness was 0.78 mm.

Fabric structure 45 x 35 (15 cm) Next, the ratio of the thickness of the fabric to the conveyor belt and the thickness after rubber coating (
0,6), that is, the thickness after coating is l,
Rubber was coated to a thickness of 3 mm. Furthermore, four layers of each of these were laminated, and the surface thereof was further covered with a cover rubber layer and then vulcanized to produce a conveyor belt.

*Conveyor belt E (invention) Made of 66 Ny 07 with strength 8.6 g/d and initial modulus 51 g/d, width (W) 1,00 mm, thickness (H
)0.36mm, the ratio (W/H) is 2.8 and 3000
A monofilament cord having a denier (D) oblate elliptical shape was used as the warp yarn. The twist is 0.

On the other hand, the weft yarn has a strength of 8.6 g/d and an initial modulus of 5.
Width (W) made of 66 nylon of 1 g/d 0,
70 mm, thickness (H) 0.25 mm.

A monofilament cord having a ratio (W/H) of 2.8 and a flat elliptical shape of 1500 denier (D) was used. The twist is O.

Using these cords, fabrics were made to have the same strength as conveyor belts A and B, and after applying adhesive and drying,
Heat treatment was performed at 220° C. under a tension of 0.3 g/d to obtain an adhesive-treated fabric having the following structure.

The elongation rate of this fabric under a 1/10 guaranteed strong load is 1
．． 5%, and the dry heat shrinkage rate at 150℃ is 2.3%.
Met.

The tensile strength of this fabric was 185 kgf/1 cm, and the thickness was 0.57 mm.

(Margin below) 40 x 35 (15 cm) Next, the ratio of the thickness of the fabric of conveyor belt A to the thickness after rubber coating (
0.6), that is, the thickness after coating is 0.0.6).
Rubber was coated to a thickness of 95 mm. Furthermore, four layers of each of these were laminated, and the surface thereof was further covered with a cover rubber layer and then vulcanized to produce a conveyor belt.

*Conveyor belt F 1260D/20 normal multifilament fiber (number of filaments: 210, filament thickness: 6D) made of 66 nylon with a strength of 9.5 g/d and an initial modulus of 45 g/d, twisted 13 times per lQcm. I used it for warp yarn.

On the other hand, the weft yarn is made of 66 nylon with a strength of 8.6 g/d and an initial modulus of 51 g/d, and has a width (W) of 0.70.
Thickness (H) 0.25m, Ratio (W/H) 2
．． 8, a monofilament cord having a flat elliptical shape of 1500 denier (D) was used. The twist is 0.

Using these cords, fabrics are made to have the same strength as conveyor bells A and B, coated with adhesive, dried, and then
The fabric was heat-treated at 220°C under a tension of 0.3 g/d to obtain an adhesive-treated fabric having the following structure.

The elongation rate of this fabric under a 1/10 guaranteed strong load is 2
．． 4%, and the dry heat shrinkage rate at 150℃ is 2.7%.
Met.

In addition, the tensile strength of this fabric is l 86 kg f /
1 cm, and the thickness was 0.75 mm.

Fabric structure 45 x 35 (15 cm) Next, the ratio of the thickness of the fabric of 9 conveyor bells I-A to the thickness after rubber coating (0,6) is adjusted so that the ratio is the same as (0,6), that is, the thickness after coating is 1
．． Rubber was coated to a thickness of 25 mm.

Furthermore, four layers of each of these were laminated, and the surface thereof was further covered with a cover rubber layer and then vulcanized to produce a conveyor belt.

*Conveyor belt G Rubber coat is applied to the fabric of conveyor belt I-D so that the weight after rubber coating is equal to that of the fabric of conveyor belt A, and this is laminated in four layers, and the surface is further covered with a cover rubber layer. After that, a conveyor belt was manufactured using jD(iFE).

Durability evaluation method Conveyor belts A, B, D, E, F, and G were run on a conveyor belt running tester 40 as shown in Figure 3, and the belt was bent up to 2 million times at the pulley portion. In Figure 3, where the residual strength of the core after the core body was measured and the retention rate with respect to the strength before running was determined, 41 is the conveyor belt, 42 is the conveyor belt.
indicates a pulley with a diameter of 200 mm, and 43 indicates a pulley with a diameter of 801 mm.
1 pulley is shown.

The elongation after running was measured in the same manner as the evaluation of the durability of the bottom length, and expressed as an index with the amount of growth of the conveyor bell L-D set as 100. Here, the smaller the index, the better.

1゜Og per unit length of conveyor belt of constant width
The amount of deflection in the thickness direction of the conveyor belt when a load of / cm was applied to the conveyor belt was measured and used as a measure of rigidity.

Heavy 1 people 1 Yodo Measure the weight per unit of conveyor belt.

The amount of weight reduction for conveyor belt D was determined.

(Left below) Table 1. Evaluation Results As is clear from Table 1 above, the conveyor heald of the present invention has reduced weight compared to conventional conveyor belts, and has improved durability when monofilament with a flat cross section is used for the warp threads. It can be seen that it has excellent growth properties, and when used as a weft, it becomes a conveyor belt with excellent rigidity.

〔Effect of the invention〕

As a result of using a monofilament cord having a flat elliptical cross-sectional shape as the fiber reinforcing layer of the conveyor belt as described above, the present invention can provide a conveyor belt that is lightweight and has excellent durability, growth, and rigidity. It is something.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an example of a conveyor belt, FIG. 2(a) is a cross-sectional view of a monofilament cord having a flat cross-sectional shape used in this invention,
1 is a cross-sectional diagram of a conventional multifilament fiber cord, FIG. 3 is an explanatory diagram showing an example of a conveyor belt running test, and FIGS. 4 and 6 are a cross-sectional diagram of a conventional multifilament fiber cord. FIGS. 5 and 7 are explanatory diagrams showing an example of a reinforcing fabric for a conveyor belt using a monofilament cord having a flat cross-sectional shape according to the present invention.

Claims (1)

[Claims] In a conveyor belt comprising at least one fiber reinforcing layer, the reinforcing layer is comprised of a monofilament cord having a substantially untwisted flat cross-sectional shape in which the warp yarn, the weft yarn, or both the warp yarn and the weft yarn are substantially untwisted. Monofilament cord width (W) to thickness (H) ratio (W/H)
A conveyor belt characterized in that the is in a range of 2.0 to 4.0.