JPH0748751A - Belt - Google Patents

Abstract

PURPOSE:To obtain a high-performance belt string having excellent dimensional stability, lightness, improved heat resistance and handleability. CONSTITUTION:This belt comprises woven fabric containing >= about 20% of warp composed of polybenzazole filament having at least 4.0GPa strength and at least >=140GPa initial modulus of elasticity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial belt used for lifting loads and the like, and more particularly to a synthetic fiber belt that can be used for heavy items.

[0002]

2. Description of the Related Art Conventionally, polyester, nylon and the like have been used as synthetic fibers for industrial belt fabrics. However, since a wide and thick belt is required for lifting heavy objects, workability is poor, It takes time to store. In addition, there is a problem that durability and safety are seriously damaged when contacting with sharp edges such as steel materials and external obstacles, resulting in frequent replacement and an increase in waste. Although metal wires may be used for such applications, there is a problem that it is difficult to dispose of used wires in addition to fatal defects such as damage to luggage and workability. Further, the conventional industrial belt fabric is not only thick and bulky, but also its use conditions are very limited due to temperature environment and the like.

[0003]

SUMMARY OF THE INVENTION The present invention is intended to provide a synthetic fiber belt which is supple and easy to handle, and which is excellent in temperature environment.

[0004]

That is, the present invention is a belt made of a woven fabric containing filaments of polybenzazole fiber having a strength of at least 4.0 GPa and an initial elastic modulus of at least 140 GPa of 20% or more of warp yarns. Is.

The polybenzazole fiber contained in the belt according to the present invention preferably has a strength of at least 4.0 GPa or more. If the strength does not reach 4.0 GPa, the single fibers constituting the belt are likely to be cut. The belt has poor durability. Conventionally, in order to improve the durability of the belt, it has been effective to thicken the monofilament constituting the woven fabric to increase the cutting strength per monofilament. However, if the monofilament is thickened to the point where the belt has sufficient durability, the yarns that make up the fabric become very hard, and the slack that occurs during sewing of the fabric tends not to be absorbed easily,
The belt itself loses its flexibility and becomes difficult to handle. In the present invention, by using the high-strength polybenzazole fiber, not only the cutting of the fiber is difficult to occur even when using a thin single fiber, and because the abrasion resistance of the fiber is excellent, the durability of the fabric is extremely high. Get higher

The polybenzazole fiber of the present invention preferably has an initial elastic modulus of at least 140 GPa or more. The effect is exerted particularly in applications where tensile strength is required, such as when the belt of the present invention is used as a sling for suspending heavy objects. For example, when a load is hung, a belt that easily stretches causes the load to move in the air and tends to lose balance. In particular, for the purpose of improving dimensional stability, a sling belt with excellent workability and safety is constructed by using a woven structure in which high-strength polybenzazole fiber having a high elastic modulus is constrained in a warp as linearly as possible. Can be

The belts of the present invention preferably contain about 20% or more polybenzazole fibers. 100 woven fabrics
% Composition of high-strength polybenzazole fiber is extremely effective in improving the strength and dimensional stability of the belt, but the weight of the belt increases and the product is subject to application restrictions. The high-strength polybenzazole fiber used in the present invention is remarkably superior in strength and elastic modulus as compared with the conventional synthetic fiber belt, so that the mechanical properties of the belt are reduced (light-weight) with the high-strength polybenzazole fiber. You can Therefore, it is extremely effective in improving the performance of a belt made of organic fibers such as polyester, polyamide, polyolefin, vinylon, polyarylate, aramid, polyimide, cotton and hemp. Further, by reinforcing inorganic fibers such as metal, glass, and ceramics, the belt's ferresibility is improved, and a high-performance belt having heat resistance, chemical resistance, and noncombustibility can be obtained. Examples of the method of combining fibers include a method of sewing different kinds of fabrics, a filament mixture, and a method of interweaving in a weaving process. When the belt is required to have particularly high strength, it is preferable to form the belt with filaments. For the composite fiber material, the material type and composition ratio can be freely selected according to the product characteristics required for the belt. For example, the weight, heat resistance, flame retardancy, chemical resistance, oil resistance, strength, elastic modulus, color tone, friction characteristics, etc. may be mentioned. Further, the weaving structure of the belt of the present invention and the sewing method can be freely created according to the purpose.

The amount of high strength polybenzazole fibers contained in the belt is preferably about 20% or more by weight. The strength per weight of the high-strength polybenzazole fiber is about 5 times that of the general-purpose high-strength fiber, and the elastic modulus thereof is about 10 times. Therefore, 20% of high-strength polybenzazole fiber exhibits the same strength as conventional materials, and the dimensional stability is approximately doubled. Therefore, when the amount of the high-strength polybenzazole fiber contained in the belt is less than about 20% by weight, the elastic modulus in the warp direction of the woven fabric cannot be sufficiently increased as compared with the conventional product. The amount of high-strength polybenzazole fiber contained in the belt is more preferably 25% or more, further preferably 30% or more. The present invention is limited by the type and number of materials to be compounded, the type of woven fabric, the method of compounding, the type and amount of oil agent or lubricant adhered or impregnated, the sewing method, and the post-processing method such as resin coating. is not.

The polybenzazole fiber used in the belt of the present invention is characterized by high heat resistance, and even if the temperature of the belt rises in use, the elastic modulus remains high up to 300 ° C. To be done. Work in a high temperature atmosphere,
A high safety factor can be maintained even when heat is accumulated in the pulley.

[0010]

EXAMPLES Hereinafter, the method for manufacturing the rope of the present invention will be specifically described with reference to examples. The strength and elongation characteristics of the raw yarn are JIS-
The method of L-1013 was followed. The breaking load of the belt sling was in accordance with the method of JIS-B-8818.

Examples 1-3 and Comparative Examples 1 and 2 The warp has 750 denier strength of 5.2 Gpa and elastic modulus of 160 G.
Using a polybenzoxazole fiber of Pa and a polyethylene terephthalate fiber of 500 denier strength 1.1 GPa elastic modulus 15.4 GPa, and setting each to the number ratio shown in Table-1, using a polyethylene terephthalate fiber of 375 denier as a weft width Woven to a 75 mm plain weave bell. The breaking strength of the woven fabric in the warp direction is sufficient when the polybenzoxazole fiber is 20% or more of the warp.

[0012]

[Table 1]

Example 4 and Comparative Example 3 1500 Denier Strength 5.2 GPa Elastic Modulus 155 GPa
Polybenzbisoxazole fiber of 1500 and polyethylene terephthalate fiber of 1500 denier strength 1.1 GPa elastic modulus 15.4 GPa are used as warp yarns at a ratio of 1 to 2 to form a belt having a width of 50 mm by using polyethylene terephthalate fiber of 1000 denier as a weft yarn.
This was sewn into an endless belt sling. As Comparative Example 3, a belt sling of the same type made of 100% polyethylene terephthalate fiber was produced. Table 2 shows the breaking strength and breaking elongation. According to the present invention, it is possible to obtain a highly safe belt sling that has little elongation even when an extremely high load is reached.

[0014]

[Table 2]

Example 5 1000 denier strength 5.1 GPa Elastic modulus 158 GPa
Polybenzbisoxazole fiber of 100 denier and strength of 3.5 GPa elastic modulus 71.4 GPa E-
A belt having a width of 25 mm was prepared by using 750 denier polybenzbisoxazole fiber as a weft yarn in which glass fibers were used as warps at a ratio of 1: 2. 2 of this fabric
The breaking strength was measured in an atmosphere of 00 ° C.
When the breaking strength was measured in an atmosphere of 300 ° C. in which the strength of the E-glass fiber was maintained at 93% with respect to the strength at 0 ° C.
The value was 89% with respect to the strength at room temperature.

[0016]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a belt which is supple yet has strength and elastic modulus comparable to that of a high-strength metal fiber and which is excellent in dimensional stability.

Claims (1)

[Claims] 1. A belt made of a woven fabric containing filaments of polybenzazole fiber having a strength of at least 4.0 GPa or more and an initial elastic modulus of at least 140 GPa or more, in an amount of about 20% or more of a warp.