JPS6036684B2 - Manufacturing method of cable gas dam part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the method of forming a gas dam in a cable consisting of a large number of plastic-coated core wires, such as electric wires and optical fibers.

First, the cable gas dam section is made by stripping 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. It is formed by In this case, since the filler has no adhesive properties to the polyethylene that is the material of the core wire sheath and sheath, in the case of a cable that forms a gas dam, the filler material is especially difficult to apply to the outer periphery of the plastic sheath as the core wire. A hot-melt resin extrusion coated with good internal adhesion to the gas dam is used, and a similar hot-melt resin is also applied on the sheath of the gas dam forming part. However, it is very troublesome to extrude and coat each core wire with adhesive hot melt resin, and adhesive hot melt resin is expensive, so it is not possible to coat core wire parts other than the gas dam part with it. It is a menstrual medicine. Furthermore, in practice, it is impossible to apply adhesive hot melt resin to only the core wires exposed by peeling off the sheath, one by one, because the core wires are crowded together. An object of the present invention is to provide a method for manufacturing a cable gas dam part that can efficiently and inexpensively form a high-quality gas dam part using an adhesive hot-melt resin coating or a normal plastic-coated core wire. It is in.

Embodiments of the present invention will be described in detail with reference to the drawings.
The figure schematically shows the method of the invention, in which the sheath 12 of the cable 10 in which the gas dam section is to be manufactured is stripped away to expose a number of plastic-coated core wires 14.

In this case, there is no need to remove the unit wrapping tape.
Next, the exposed core wire portion 16 is placed into a gas plasma processing apparatus 18 shown in FIG.

This device includes a cylindrical casing 20 and airtight flanges 22, 22' that are detachably attached to both ends of the cylindrical casing 20, and treats the exposed core portion 16 of the cylindrical casing by being gripped by the airtight flanges 22, 22'. Position within the chamber 24. The processing chamber 24 is evacuated by the vacuum pump 28 through the suction ports 26 and 26', and then the gas cylinder 3
Gases such as oxygen, helium, and argon are injected from zero through gas inlets 32, 32'. The processing chamber 24 also has electrodes 34 and 36 with the ○ line exposed portion 16 in between,
One electrode 34 is connected to a high frequency generator 38, and the other electrode 36 is grounded. Gas is continuously injected,
This gas is turned into plasma between the electrodes 34 and 36, and this plasma-turned gas activates the surfaces of the plastic-coated core wire 14, the sheath 12, the unit wrapping tape, and the core wrap inside the processing chamber 24.

Surprisingly, when this gas plasma treatment is performed, not only the surfaces of the core wires located outside the core wire east but also the surfaces of the core wires located inside the core wire are almost uniformly activated. Thereafter, this cable is removed from the plasma processing apparatus 18, placed in a mold (not shown), and a filler such as epoxy or urethane is filled across the exposed core portion 16 and the sheath portions on both sides thereof. The principle of activating the core wire exposed portion 16 to be filled with the filler material, the sheath portions on both sides thereof, the unit wrapping tape, and the core wrap by gas plasma treatment is as follows.
When a polymer material and an oxidizing plasma such as oxygen come into contact, the following reactions '11 to [6] are performed.

Rapid RH+○・→R'10R○・or R・10OH・
{1' Rapid R・10○・→R0・
t21 slow RH・→R・10 days・or R・R′・
'3' Rapid R・102→RO0・
■ROO. 10R'H→ROOH+R'・
[51 Slow ROOH→R0・OH・
{61 In the above formula, R represents an alkyl group of the polymer material.

In this way, the radicals, -OH, and oxides generated on the surface of the polyethylene, which is the material of the core wire coating and sheath, react with the hardening agent (isocyanate) of the filler, resulting in high adhesiveness. On the other hand, when the polymeric material is exposed to respective plasmas of an inert gas such as helium and an enzyme, the following reactions (12) are performed.

1CH2CH210He* →-CQCH-+Sun/10th e '71-
CH2C・H−10 days・→−CH=CH−+日2 '8
}-CQCH2-10*→-CH2C・day×日0・Thus, the polyethylene surface becomes a crosslinked foundation and unsaturated bonds are formed, which improves the adhesion when reacted with the hardening agent of the filler.

In a specific example of the present invention, the cable 10 is placed in the gas plasma processing apparatus 18 shown in FIG.
The electrode was evacuated to a vacuum level, and while helium gas was injected at a flow rate of 15 som/min, a high frequency output of 13.58 MHz Fox W was applied to the electrode to perform helium plasma treatment for 10 minutes.

After this treatment, a urethane filler was filled, and the adhesive strength between the filler and the cable's plastic-coated core was approximately 500.
It was evening/depression. Furthermore, when oxygen plasma treatment was applied, the adhesive strength was approximately the same, 500 μm/arc. However, without gas plasma treatment, the adhesive strength was 1/10 or less. In FIG. 2, both ends of the casing 20 of the gas plasma processing apparatus 18 are left open, and the casing 20 is slightly narrowed. At both ends, a vacuum is drawn using the vacuum suction port 26a to prevent outside air from entering the processing chamber 24, and from the middle, a vacuum is drawn. The processing is performed by drawing the inside of the processing chamber 24 to a predetermined degree of vacuum using the suction port 26. In the above embodiments, the gas is, for example, CF
By using No. 4, foreign matter (for example, Si) adhering to the surface to be processed can be etched, so it can be applied to surface cleaning.

Further, in the above embodiment, it was shown that the exposed portion of the core wire and the sheath portions on both sides thereof were subjected to plasma treatment at the same time, but the present invention is not limited to this.
Other adhesive properties may be applied to the sheath portions on both sides. However, the former has much higher manufacturing efficiency.
According to the present invention, the core wires exposed by peeling off the sheath forming the gas dam can be treated all at once to give adhesive properties, so manufacturing of the gas dam is extremely efficient. It is economical because a plastic-coated core wire without a final resin coating can be used.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one step of the method of the present invention, and FIG.
It is a sectional view of a modified example of the device used in the same process as the figure. 10... Cable, 12... Sheath, 14... Plastic coated core wire, 16... Core wire exposed portion, 18...
...Gas plasma processing equipment. Figure 1 Figure 2

Claims (1)

[Claims] 1. A method for manufacturing a cable gas dam section, in which the sheath of the cable is peeled off to expose a large number of plastic-coated core wires, and a filler is filled across the exposed core wire portion and the sheath portions on both sides thereof to form a gas dam section. A method of manufacturing a cable gas dam section, characterized in that the exposed core wire section is put into a gas plasma processing apparatus and subjected to gas plasma treatment, and then filled with the filler.