JPH11227919A - Cloth reinforced conveyer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cloth reinforced conveyer which has a small extension in service time, has an excellent antibending fatigue property, and can be manufactured at a low cost. SOLUTION: This conveyer belt has a reinforcing material layer 2 made by laminating a first reinforcing cloth 3 whose raw material in the belt longitudinal direction consists of a polyamide fiber, and a second reinforcing cloth 4 whose raw material in the longitudinal direction consists of a polyester fiber or a PVA fiber. The laminating numbers of the reinforcing cloth are 3 to 6, and the outermost layer is composed of the first reinforcing cloth 3, while the inner layer is composed of the second reinforcing cloth 4. The ratio F2 /F1 of the total rupture strength F2 of the second reinforcing cloth 4 and the total rupture strength F1 of the first reinforcing cloth 3 is made higher than 0.4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveyor belt reinforced by a reinforcing cloth, and more particularly, to a first reinforcing cloth made of polyamide fiber in the longitudinal direction of the belt as the reinforcing cloth, and a material in the longitudinal direction of the belt. The present invention relates to a conveyor belt in which, when used in combination with a second reinforcing cloth made of polyester fiber or polyvinyl alcohol fiber, elongation during use is reduced and bending fatigue resistance is enhanced.

[0002]

2. Description of the Related Art Conventionally, as a cloth-reinforced conveyor belt,
Generally, a polyamide cloth reinforced belt reinforced with a reinforcing cloth made of polyamide fiber, a polyester cloth reinforced belt reinforced with a reinforcing cloth made of polyester fiber, and a polyvinyl alcohol cloth reinforced belt reinforced with a reinforcing cloth made of polyvinyl alcohol fiber It is known that each has the following features.

Features of polyamide cloth reinforced belt Advantages: Low cost per breaking strength and excellent bending fatigue resistance. Disadvantages: Large elongation (creep) during use. For this reason,
The capacity of the belt body's elongation absorber must be increased. Features of polyester cloth reinforced belt and polyvinyl alcohol cloth reinforced belt Advantages: Elongation (creep) during use is small. Disadvantages: High cost per break strength compared to polyamide fabric reinforced belts. Also, the bending fatigue resistance is inferior to that of the polyamide cloth reinforced belt. For this reason, in particular, in the case of a multilayer structure, the bending strain received at the time of bending becomes large. However, in this case, the amount of yarn constituting the polyester cloth increases, and the cost becomes much higher than that of the polyamide cloth.

[0004]

As described above, both the polyester cloth and the polyvinyl alcohol cloth as the reinforcing cloth of the cloth reinforced conveyor belt and the polyamide cloth have advantages and disadvantages. In the reinforcing material layer of the cloth reinforced conveyor belt,
It is desired to have both low elongation as low as polyester cloth or polyvinyl alcohol cloth and low cost and flex fatigue resistance as low as polyamide cloth. Conventionally, those satisfying all these properties have been provided. Not.

[0005] That is, the required properties of the reinforcing material layer of the cloth reinforced conveyor belt are not necessarily constant depending on the position (for example, the laminating position such as the outer layer side or the inner layer side). In a cloth reinforced conveyor belt, the same reinforcing cloth is laminated to form a reinforcing material layer. Conventionally, the cloth to be used is optimized according to the position of the reinforcing material layer, that is, according to the required characteristics according to the laminating position. There is no technical idea to change.

[0006] A reinforcing belt composited by twisting of polyester fibers and polyamide fibers and a conveyor belt using a reinforcing cloth composited by weaving using both polyester fibers and polyamide fibers have been studied. However, since all of them are composites within the same reinforcing cloth, there is a drawback that the processing at the time of manufacturing the reinforcing cloth is complicated, the number of steps is large, and the cost is high. Even when a polyvinyl alcohol fiber and a polyamide fiber are compounded in the same reinforcing cloth, there is a similar defect.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide a cloth-reinforced conveyor belt which is small in elongation during use, excellent in bending fatigue resistance and can be manufactured at low cost.

[0008]

A cloth reinforced conveyor belt according to the present invention is a cloth reinforced conveyor belt having a reinforcing material layer formed by laminating a plurality of reinforcing cloths. Has a first reinforcing cloth made of polyamide fiber and a second reinforcing cloth made of polyester fiber or polyvinyl alcohol (PVA) fiber as a material in the belt longitudinal direction, and the reinforcing cloth forming the reinforcing material layer is laminated. The number is 3 to 6, and among the reinforcing cloths constituting the reinforcing material layer, at least the outermost reinforcing cloth on the front and back sides is a first reinforcing cloth,
The reinforcing cloth on the inner layer side is a second reinforcing cloth, and the total breaking strength F per unit width of the second reinforcing cloth constituting the reinforcing material layer.
₂ and the total breaking strength F ₁ per unit width of the first reinforcing cloth (hereinafter referred to as “inner layer / outer layer breaking strength ratio”) F ₂ /
F ₁ is characterized in that at least 0.4.

In the following, the first reinforcing cloth made of a material in the longitudinal direction of the belt made of polyamide fiber is called "polyamide cloth", and the reinforcing cloth made of the material of the belt in the longitudinal direction made of polyester fiber is called "polyester cloth". In some cases, a reinforcing cloth in which the material in the belt longitudinal direction is made of polyvinyl alcohol fiber is referred to as “PVA cloth”. The fibers arranged in the belt longitudinal direction are called "warp yarns", and the fibers arranged in the belt width direction are called "weft yarns".

In the present invention, the second reinforcing cloth may be made of only polyester cloth or PVA cloth, or may be a combination of polyester cloth and PVA cloth.

As shown in FIG. 2, when the conveyor belt 10 is bent while passing through the pulley 20 while traveling, the bending strain (ε) which the reinforcing material layer 11 in the conveyor belt 10 receives is obtained by the following equation. .

Ε = t / RR R: bending radius from neutral axis t: distance from neutral axis to center of each reinforcing cloth Since neutral axis is the center of reinforcing material layer 11 in the thickness direction, reinforcing cloth of outer layer The greater the t value, the greater the bending strain (ε) received. That is, the bending condition is more severe for the outer layer of the reinforcing cloth.

In the present invention, the problem caused by bending distortion is solved by arranging a polyamide cloth having good resistance to bending fatigue on at least one outer upper and lower reinforcing cloth having severe bending conditions.

On the other hand, the inner layer of the reinforcing material layer is closer to the neutral axis than the outer layer and has a small t value, so that the bending strain (ε) received is small. Therefore, a low-elongation polyester cloth and / or
Alternatively, a PVA cloth is arranged. By making the total breaking strength of the polyester cloth and / or PVA cloth of the inner layer 40% or more of the total breaking strength of the polyamide cloth used for the outer layer, the entire elongation of the reinforcing material layer can be reduced. I found it.

In this case, the bending fatigue resistance of the polyester cloth and the PVA cloth is inferior to that of the polyamide cloth, but since it is located in the inner layer having a small bending strain, there is no fear of fatigue cutting or the like.
Further, since there is no need to improve the fatigue resistance in terms of the fabric structure unlike the ordinary polyester fabric for a multi-layer belt or PVA fabric, an inexpensive conveyor using a polyester fabric or PVA fabric that is cheaper than a usual polyester fabric or PVA fabric. Belts can be provided.

In the present invention, the breaking strength is measured in accordance with JIS K6322-1988 for a cloth sample in which each reinforcing cloth is peeled off from the conveyor belt to form one layer.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIGS. 1A to 1D are schematic sectional views showing an embodiment of a cloth-reinforced conveyor belt of the present invention.
Although FIG. 1 illustrates a case where only the polyester cloth 4 is used as the second reinforcing cloth, in the present invention, the second reinforcing cloth may be made of only the polyester cloth as shown in the drawing. Further, it may be composed of only PVA cloth, or may be a combination of polyester cloth and PVA cloth.

As shown in the figure, the cloth reinforced conveyor belt of the present invention comprises a reinforcing cloth (a polyamide cloth 3 as a first reinforcing cloth and a polyester cloth 4 as a second reinforcing cloth) between upper and lower cover rubbers 1A and 1B. ) Are interposed with the reinforcing material layer 2 laminated thereon.

In the present invention, the number of layers of the reinforcing cloth constituting the reinforcing material layer 2 is 3 to 6. When the number of laminations is 2 or less, the polyamide cloth 3 and the polyester cloth 4 cannot be used together to form the front and back outer layers with the polyamide cloth, and when the number is 7 or more, both the elongation and the bending fatigue resistance are poor. It is difficult to improve.

In the cloth reinforced conveyor belt of this embodiment, a polyamide cloth 3 is used as an outer reinforcing cloth of the reinforcing material layer 2, and a polyester cloth 4 is used as an inner reinforcing cloth. The arrangement of the reinforcing cloth is not particularly limited as long as the polyamide cloth 3 is disposed in the outer layer and the polyester cloth 4 is disposed in the inner layer. For example, in the case of a three-layer reinforcing material layer, as shown in FIG. 1 (a), a polyamide cloth 3 / polyester cloth 4 / a polyamide cloth 3 is obtained. As shown, it is preferable to use polyamide cloth 3 / polyester cloth 4 / polyester cloth 4 / polyamide cloth 3.

In the case of six reinforcing material layers, FIG.
As shown in (c), polyamide cloth 3 / polyester cloth 4
/ Polyester cloth 4 / polyester cloth 4 / polyester cloth 4 / polyamide cloth 3, and FIG.
As shown in the figure, a polyamide cloth 3 / polyamide cloth 3 / polyester cloth 4 / polyester cloth 4 / polyamide cloth 3 / polyamide cloth 3 may be used. In general, it is preferable to arrange the reinforcing cloth so as to be symmetrical with respect to the center line in the thickness direction of the reinforcing material layer 2. Therefore, in the case of five reinforcing material layers, polyamide cloth / polyester is used. Cloth / Polyester cloth /
It is preferable to use polyester cloth / polyamide cloth or polyamide cloth / polyamide cloth / polyester cloth / polyamide cloth / polyamide cloth.

In the above description, the same can be said for the case where a part or the whole of the polyester cloth is replaced with the PVA cloth.

In the present invention, as the polyester cloth, at least the warp is made of polyethylene terephthalate (P
A woven fabric made of polyester such as ET) and polyethylene naphthalate (PEN) can be used. The polyester cloth may be such that only the warp is made of PET, PEN, or the like, and both the warp and weft are made of PET, PE.
N or the like. Only warp is PET,
In the case of a polyester cloth made of PEN or the like, weft yarns include polyamide such as 6-nylon, 6,6-nylon, 4,6-nylon, and MXD6 nylon, polyvinyl alcohol such as vinylon, rayon, cotton, and E / C blend. Etc. can be used.

As the PVA cloth, a woven cloth in which at least the warp is made of PVA such as vinylon can be used. In this PVA cloth, only the warp may be made of vinylon or the like, or both the warp and the weft may be made of vinylon or the like. In the case of a PVA cloth in which only the warp is made of vinylon or the like, the weft is 6-nylon,
Polyamides such as 6,6-nylon, 4,6-nylon, and MXD6 nylon, polyesters such as PET and PEN, rayon, cotton, and the like can be used.

As the polyamide cloth, a woven cloth in which at least the warp yarn is made of polyamide such as 6-nylon, 6,6-nylon and 4,6-nylon can be used. In this polyamide cloth, only the warp may be made of 6-nylon or the like.
-It may be made of nylon or the like. When the warp is a polyamide cloth composed of 6-nylon or the like, the weft may be polyester such as PET or PEN, PVA such as vinylon, rayon, cotton, or the like.

The weft yarn of each reinforcing cloth is not limited to ordinary yarn (filament yarn or spun yarn), but may be nylon, vinylon, P
Monofilament yarn such as ET can also be used.

There is no particular limitation on the weave of these reinforcing cloths, and any of plain weave, straight warp weave, twill weave, and blind weave may be used.

There are no particular restrictions on the number of twists or the basis weight of the fibers constituting the reinforcing cloth, and any design may be used as long as it satisfies the above-mentioned breaking strength ratio.

Usually, as the first reinforcing cloth, the polyamide cloth, the breaking strength per unit width is 100 to 400.
It is preferably about kg / cm. Such a polyamide cloth is usually 0.5 to 1.5 mm in thickness as a plain weave, the number of shots is 30 to 100/5 cm, 15 to 40/5 cm, and the basis weight is 200. About 1000 g / m ² .
Further, as the second reinforcing cloth, a polyester cloth or a PVA cloth, the breaking strength per unit width is 50 to 700 kg /.
cm or so, and such a polyester cloth or PVA cloth usually has a thickness of 0.5 to 2.5
mm, number of shots 30 to 100 length / 5cm, width 15
It is about 40 to 5 cm and the basis weight is about 150 to 2000 g / m ² . However, these fabric structures naturally differ depending on the weave.

In the present invention, the inner layer / outer layer breaking strength ratio F of the second reinforcing cloth made of polyester cloth and / or PVA cloth and the first reinforcing cloth made of polyamide cloth is used.
₂ / F ₂ is 0.4 or more, but if the strength ratio F ₂ / F ₁ is too large, it is disadvantageous in terms of cost.
₂ / F ₁ is preferably in the range of 0.4 to 10.0.

The cloth reinforced conveyor belt of the present invention has the same structure as the conventional cloth reinforced conveyor belt except that the reinforcing cloth has a reinforcing material layer as described above. It can be manufactured by a method in which a reinforcing material layer in which an unvulcanized adhesive rubber is sandwiched between two cloths is interposed between two unvulcanized cover rubbers, and heated under pressure to perform vulcanized adhesive integration. .

The rubber material of the cover rubber is not particularly limited, and natural rubber, butyl rubber, styrene / butadiene rubber (SBR), nitrile / butadiene rubber (NB)
R), a synthetic rubber such as ethylene / propylene rubber (EPR), or a blend rubber thereof can be used.

The ratio of the thickness of the cover rubber to the reinforcing material layer, etc.
Although it varies depending on the purpose of use of the cloth-reinforced conveyor belt, in a normal case, the total thickness of the reinforcing material layers in which the reinforcing cloth is laminated is 0.2 to 1.0 cm, and the thickness of the upper (table) cover rubber is 0. It is preferable to use a cloth-reinforced conveyor belt having a thickness of 0.3 to 1.0 cm, a lower cover rubber having a thickness of 0.2 to 0.4 cm, and a total of 0.7 to 2.4 cm.

[0035]

The present invention will be described more specifically below with reference to examples and comparative examples.

The reinforcing cloths used in the following examples and comparative examples are as follows, and the breaking strength per unit width of each reinforcing cloth is shown in Table 1.

Polyamide cloth A: Plain woven cloth of both 6,6-nylon fiber warp and weft Polyamide cloth B: Plain woven cloth of 6,6-nylon fiber warp and PVA fiber polyamide cloth C: 6 warp yarn Polyester cloth A: Plain woven cloth of PET fiber for both warp and weft Polyester cloth B: Plain woven cloth of PET fiber for weft and 6,6-nylon
Straight warp woven cloth of nylon fiber Polyester cloth C: Twill woven cloth of PET fiber and weft of vinylon polyester Polyester cloth D: PET fiber of warp and 6,6- weft
Plain woven cloth of nylon fiber Polyester cloth E: Blind woven cloth of PET fiber and weft yarn of E / C blend fiber PVA cloth: Plain woven cloth of vinylon fiber and weft yarn of 6,6-nylon fiber Aramid cloth: Warp yarn Is an aramid (aromatic polyamide) fiber and a straight warp woven fabric with a weft of 6,6-nylon fiber Polyarylate cloth: a straight warp woven fabric with a warp yarn of a polyarylate (wholly aromatic polyester) fiber and a weft yarn of PET fiber Example 1 -10, Comparative Examples 1-7 The reinforcing cloth shown in Table 1 was laminated between two unvulcanized rubbers (thicknesses 0.8 cm and 0.3 cm) in the number shown in Table 1.
30 kg / cm with a reinforcing material layer containing adhesive rubber interposed
^2. By heating and pressing at 150 ° C. for 0.5 hour, they were vulcanized and bonded together to produce a cloth reinforced conveyor belt having a reinforcing cloth breaking strength and an inner layer / outer layer breaking strength ratio shown in Table 1.

The breaking strength and creep characteristics of this cloth reinforced conveyor belt (load of 1/30 of the conveyor belt strength was 2
Elongation (%) when loaded for 0 days), strength retention after bending (pulley diameter: 400 mm, load: 1/15 of the conveyor belt strength), each reinforcement of the reinforcing material layer after bending 3 million times The strength retention rate of the cloth (100% before bending) (%)), the cost index per strength (the cost required for the cloth-reinforced conveyor belt of Comparative Example 1 with a conveyor belt strength of 1319 kg / cm is 100). ) And the results are shown in Table 2.

[0039]

[Table 1]

[0040]

[Table 2]

The following are clear from Tables 1 and 2.

That is, in Examples 1 to 10 in which the outer layer polyamide cloth and the inner layer polyester cloth or PVA cloth were used in combination and the inner layer / outer layer breaking strength ratio was 0.4 or more, the creep of the conveyor belt was 0.7 to 1 0.05%, which is at the same preferable level as that of the conventional polyester cloth reinforced belt (Comparative Examples 1 and 2). In addition, compared to 2.3% of the conventional polyamide cloth reinforced belt (Comparative Example 3), the low elongation is less than half. Further, the strength retention after bending was maintained at 80% or more in each layer, and good results equivalent to the polyamide cloth reinforced belt of Comparative Example 3 were obtained. Moreover, the cost index is 82
As low as 94, the cost is almost as low as that of a polyamide-reinforced belt, and there is no problem in terms of economy.

Comparative Example 1 is a conventional polyester cloth reinforced belt in which five layers of polyester cloth are laminated, and the strength retention after bending is significantly higher than that of the fifth outermost layer of the lowermost polyester cloth which is greatly subjected to compressive bending strain. (Retention rate 2
4%), and there is a risk of fatigue cutting in practical use.

Comparative Example 2 is a conventional polyester cloth reinforcing belt of a type in which the weaving ratio of the polyester cloth is added to a certain amount or more and the bending fatigue property is improved, and the strength retention after bending is 79% or more for each layer. Although there is no problem, the cost index per strength is significantly higher at 118, which is not economical.

Comparative Example 3 is a conventional polyamide cloth reinforced belt in which only six layers of polyamide cloth are laminated, and there is no problem in the strength retention after bending and the cost index per strength, but the creep is significantly inferior.

Comparative Example 4 uses a polyamide cloth and a polyester cloth in combination, but has an inner layer / outer layer breaking strength ratio of 0.3. In this case, the creep is 1.7%, which is the level of a polyamide cloth reinforcing belt. Slightly approached and insufficient low elongation.

In Comparative Example 5, a polyamide cloth was laminated on each of the upper and lower layers of the reinforcing material layer, and a polyester cloth was laminated on five inner layers, so that the total number of laminated layers was seven. 7
Since the layer is a polyamide cloth, the strength retention after bending is 7
Although it retains 6%, the inside of the 6th-layer polyester cloth is significantly reduced and cannot withstand actual use.

In Comparative Examples 6 and 7, a polyamide cloth was used for each of the upper and lower layers of the outer layer of the reinforcing material layer, and an aramid cloth or a polyarylate cloth was used for the inner layer. Although there is no problem, the cost index per strength is significantly higher and not economical.

[0049]

As described above in detail, according to the cloth reinforced conveyor belt of the present invention, the polyamide having good bending fatigue resistance can be used as the reinforcing cloth of the outer layer which is greatly subjected to bending strain among the reinforcing cloths constituting the reinforcing material layer. A low-stretch polyester fabric and / or a PVA fabric as the inner layer reinforcing cloth near the neutral axis and having a small bending strain, and an inner layer / outer layer breaking strength ratio F _{2 of} both reinforcing cloths.
By setting / F ₁ to 0.4 or more, it becomes possible to provide a belt which has a small elongation at the time of use and has no problem in bending fatigue, at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a cloth-reinforced conveyor belt of the present invention.

FIG. 2 is an explanatory diagram of bending strain applied to a conveyor belt.

[Explanation of symbols]

 1A, 1B Cover rubber 2 Reinforcement layer 3 Polyamide cloth (first reinforcing cloth) 4 Polyester cloth (second reinforcing cloth)

Claims (1)

[Claims] 1. A cloth reinforced conveyor belt having a reinforcing material layer formed by laminating a plurality of reinforcing cloths, wherein the reinforcing material layer comprises: a first reinforcing cloth made of polyamide fiber in a belt longitudinal direction; A longitudinal reinforcing material having a second reinforcing cloth made of polyester fiber or polyvinyl alcohol fiber, wherein the number of layers of the reinforcing cloth constituting the reinforcing material layer is 3 to 6; Among the cloths, at least the outermost reinforcing cloth on the front and back is the first reinforcing cloth, and the reinforcing cloth on the inner layer side is the second reinforcing cloth. A unit of the second reinforcing cloth constituting the reinforcing material layer a breaking strength F ₂ total per width, fabric reinforced conveyor ratio F ₂ / F ₁ of the breaking strength F ₁ total per unit width of the first reinforcing fabric, characterized in that at least 0.4 belt.