JPS6012609A - Method of producing gas dam cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention is directed to improving the adhesive strength between the dam-forming resin and the plastic-coated core wire when forming a gas dam part in a cable consisting of a large number of plastic-coated core wires such as electric wires and optical fibers. The present invention relates to an improvement in the plasma treatment in a method for manufacturing a gas dam cable in which the plastic coating surface is activated by gas plasma treatment in order to improve the performance.

[Prior art]

Generally, a cable gas dam is formed by peeling off the cable sheath to expose a large number of plastic-coated core wires, and then filling the exposed core wires and the sheath parts on both sides with a filler such as epoxy or urethane. be done. However, in this case, since there is no adhesiveness between the filler and the polyethylene that is the material of the core wire wave Φ and sheath, the core wire is exposed before being filled with the filler material in order to improve the adhesiveness. A method in which plasma treatment is not performed on the sheath portion and the sheath portions on both sides (patent application 1983-
No. 33980) has already been proposed.

This method will be explained with reference to FIG. FIG. 1 is a sectional view showing a state in which a part of a cable is subjected to plasma treatment using a conventional plasma treatment apparatus. When forming a gas dam using this conventional device, the sheath 2 of the portion of the cable 1 where the gas dam is to be formed is peeled off to expose a large number of plastic-coated core wires. The stiff core wire exposed portion 3 is inserted into the plasma processing container 4. The plasma processing container 4 has a container body 6, and lids 8, 8, which are provided at both ends of the container body 6 via an O-ring 7 for a knoll and have a cable through hole in the center. After positioning the core wire exposed portion 3 at approximately the center inside the plasma processing container 4, the gap between the cable through hole of the lid 8 at both ends and the cable 1 is sealed with a sealing tape 9. Thereafter, the inside of the plasma container 4 is evacuated by the vacuum pump 11 through the suction pipe 10. After starting evacuation, active gas and inert gas are sent from the gas cylinder 15 through the delivery pipe 16 into the plasma processing container 4, and when the degree of vacuum inside the container 4 becomes stable, the high frequency generator 17 supplies the gas to the plasma generating section 18. Generates plasma.

The gas plasma is introduced into the plasma processing container 4 through the delivery tube 16 and activates the surface of the exposed core portion 3 and the sheath portions at both ends thereof.

However, as shown in FIG. 1, when the suction pipe 1o and the gas plasma delivery pipe 16 are opened almost at the center of the plasma processing container 4, the treatment condition is good in the central part of the exposed core part 3, but the treatment condition at both ends is poor. In parts E and F, the plasma density was low, so the processing was uneven and insufficient.

Generally, in a gas dam cable, gas is sealed in the upper side of the cable, that is, on the side A of cable 1 in FIG. Therefore, it is necessary to increase the gas plasma density and apply uniform plasma treatment to part E in Fig. 1. However, as mentioned above, in the conventional method, part E at the end of the exposed core part is Sufficient plasma processing is not possible, and as a result, processing time is wasted unnecessarily.

[Purpose of the invention]

In view of the above-mentioned problems, an object of the present invention is to provide a method for manufacturing a gas dam cable that increases plasma density and performs efficient and uniform plasma treatment on the portion where gas-tightness is most required. It is in.

[Structure of the invention]

In order to achieve the above object, the present invention involves stripping off the sheath of a cable to expose a large number of plastic-coated core wires, and placing the exposed core wires and the sheath portions on both sides of the core wires in a gas plasma processing apparatus to treat gas. In the method for manufacturing a gas dam cable, the gas dam cable is formed by filling the exposed core part and the sheath parts on both sides thereof with a filler after plasma treatment to form a gas dam part. The plasma density is made higher in the part of the sheath part that requires gas-tight reliability than in other parts.

Examples of the invention] Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a cross-sectional view of one embodiment of the present invention, and FIG. 3 is a cross-sectional view of another embodiment. As shown in FIG. 2, in the present invention, the sheath 2 of the cable 1 where the gas dam part is to be formed is peeled off to expose a large number of plastic-coated core wires. Position in the center. If we assume that the gas-filled side of the cable is side A in Figure 2, it is section E that requires the most reliable gas-tightness. Therefore, the opening of the plasma delivery tube [6] is placed in the E section consisting of the side end of the exposed core portion 30A and the sheath portion adjacent thereto, and the opening of the suction tube 10 for evacuation is also placed in the E section. Move to the department side. In this case, the opening of the suction pipe 10 is either opposed to the opening of the delivery pipe 6, or slightly inside, that is, slightly closer to the center of the exposed core portion 3 than the opposing position.

Note that if the plasma density is moved to the outside of the facing position, the plasma density of the exposed core portion 3 will be lower than the plasma density of the sheath≦a, which is not very preferable. In yet another embodiment, as shown in FIG.
1 and the plasma delivery tube 16' are prepared, and the opening of the delivery tube 16' is placed at the E section of the cable 1, as in the case of FIG. 2 described above. The positional relationship between the opening of the delivery pipe 16' and the opening of the suction pipe 10 of the evacuation pump 11 is the same as in the case of FIG. 2 described above.

Naturally, the embodiment shown in FIG. 3 has a higher plasma density in the plasma container than the embodiment shown in FIG. 2, and plasma processing can be performed stably, but the equipment is expensive. On the other hand, the embodiment shown in FIG. 2 has the advantage of being inexpensive in terms of equipment. Therefore, the device shown in FIG. 2 and the device shown in FIG. 3 are used depending on the thickness of the cable, the required quality of the gas dam cable, etc.

As mentioned above, the opening of the plasma delivery pipe is provided in the part of the gas dam where airtightness is most required, and the suction pipe opening is provided at a position directly opposite the delivery pipe, thereby achieving the most airtightness. The plasma density in the area to be activated becomes high, and as a result, the area can be activated uniformly and efficiently in a short time. As a result, when the plasma treatment part is filled with resin such as epoxy or urethane after the plasma treatment,
Since the portions that require the most airtightness are evenly and strongly adhered to the filled resin, the airtightness is improved and stabilized.

[Effects of the Abolition of Ming]

As described above, according to the present invention, the part that requires the most airtightness in the gas dam part of the gas dam cable can be efficiently and
Moreover, it can be uniformly activated by plasma. As a result, a highly reliable gas dam cable can be obtained.

[Brief explanation of the drawing]

Fig. 2 is a vertical cross-sectional view of a cable being subjected to plasma treatment using a conventional plasma processing apparatus, Fig. 2 is a longitudinal cross-sectional view of an embodiment according to the present invention, and Fig. 3 is a longitudinal cross-sectional view of another embodiment of the present invention. It is a longitudinal cross-sectional view without showing. 1... Cable, 3... Core wire exposed part, 4... Plasma processing container, 10... Suction pipe, 11... Vacuum pump, Fig. 1 5 Fig. 2 5

Claims (1)

[Claims] The sheath of the cable is peeled off to expose a large number of plastic-coated core wires, and the exposed core wire and the sheath parts on both sides are placed in a gas plasma treatment device and subjected to gas plasma treatment, and then the exposed core wires are removed. In a manufacturing method of a gas dam cable, in which a gas dam part is formed by filling a filler material across a core wire exposed part and sheath parts on both sides thereof, gas-tight reliability is required between the exposed core part and the sheath parts on both sides thereof. A method for manufacturing a gas dam cable, characterized in that the plasma density in the part where the gas dam cable is made is higher than in other parts.