JPS6128335Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a cable jacket covering the outer periphery of a cable core.

The cable jacket is provided for the purpose of protecting the cable core and is also called a protective jacket.
This cable jacket is normally desired to have the function of protecting the cable core as much as possible from the influences of the outside world such as outside air, water, light, heat, external pressure, and external force.
Metal sheaths such as aluminum and plastic sheaths such as vinyl chloride and polyethylene are in practical use, but which of these materials to choose is a matter of
Generally, it is determined individually depending on the characteristics of the cable core to be protected or the external environment where the cable is installed.

Now, let's focus on the plastic jacket among the cable jacket materials mentioned above.As a result of the recent rise in petroleum prices, the price of plastic materials has also increased significantly, making it even more desirable to use materials economically. It is rare.

Usually, plastic jackets are made of carbon, whether they are vinyl chloride or polyethylene, under sufficient quality control to prevent deterioration of the cable core or jacket material from the effects of sunlight and other ultraviolet rays. A high grade weather resistant plastic material dispersed therein is used, but this material is generally more expensive than the plastics used in films, molded articles, insulating materials, etc.

The thickness of the outer jacket is usually determined depending on the type of cable core housed inside or the external force applied to the cable from the outside during or after installation, but in general, a thin wall thickness is 1.5 mm thicker. In this case, it is 4 to 5 mm. In the case of cords and other cables used indoors or inside equipment, they may be thin, but when looking at the cable as a whole, the amount of material used in such usage is small. Once the type of cable core has been determined, the largest determining factor for the thickness of the jacket is the force applied during or after installation, and it must be thick enough to resist such external forces. However, the amount of carbon dispersed in the material does not matter much.

On the other hand, it is sufficient that the weatherproof layer that protects the cable core or cable sheathing material from sunlight etc. prevents light from passing into the cable core, and a thickness of 0.5 mm is sufficient. .

The present invention was developed based on the above-mentioned situation, and the cable sheath of the present invention has a two-layer structure, the outer layer is made of a high-grade weather-resistant plastic layer, and the inner layer is made of a material of lower quality than the outer layer material. It is characterized in that it consists of plastic material layers, and the inner and outer layers are integrated by welding.

Hereinafter, it will be explained in detail using examples.

FIG. 1 shows an embodiment of a cable having a cable jacket according to the present invention, where 1 is a cable core, 2 is a cable jacket, 2-1 is an outer layer, and 2-2 is an inner layer.

As the material for the outer layer 2-1, a weather-resistant plastic material containing several percent of carbon is used.
As the outer layer material, it is desirable to use a new material that is manufactured in a process with sufficient quality control and whose carbon content, carbon dispersion, etc. are well controlled. Further, it is sufficient that the thickness of this outer layer is 0.5 mm or more. Next, as the material for the inner layer, it is sufficient to use a material lower in grade than the material for the outer layer, and plastic materials recovered from cable scraps or the like can be used. In addition,
As this inner layer material, it is not necessary to add a certain amount of carbon to make it weather resistant, so a material mixed with cable waste sheath material or insulating material can be used.

However, when using plastics recovered from cable scraps, it is necessary to screen and wash them to prevent foreign substances other than plastics from getting mixed in as much as possible.

The inner layer and outer layer are manufactured by connecting two extruders to one crosshead to simultaneously coat the inner layer and outer layer on the cable core.
The outer layer material is extruded so that the interface between the inner and outer layers is melted and integrated. By doing this, there is no possibility that the interface between the inner layer and the outer layer material will peel off, the inner layer and the outer layer will be stretched separately due to cable bending, etc., and a part of the outer layer or the inner layer will buckle.

Therefore, even with a two-layer cable jacket, the same thickness as a single-layer cable jacket is sufficient.

As mentioned above, the cable jacket of the present invention has the same mechanical strength as the conventional cable jacket, and low-grade materials can be used as the inner layer material, so the materials are inexpensive and are effective in terms of saving resources. It has a large economic effect.

[Brief explanation of drawings]

Figures 1A and 1B are examples of a cable having a cable jacket according to the present invention, and Figure 1 is a sectional view, and Figure 1B is a perspective view.In the figures, 1 is a cable core, 2 is a cable jacket, and 2-1 is a cable jacket. The outer layer and 2-2 indicate the inner layer.

Claims (1)

[Scope of utility model registration request] The cable sheath provided on the outside of the cable core consists of two layers: an inner and outer layer, the outer layer is a plastic layer of 0.5 mm or more thick made of a new material containing carbon, and the inner layer is a plastic layer containing recycled plastic recovered from cable scraps, etc. A cable jacket comprising layers, the inner layer and the outer layer being integrated by welding.