CN102540370B - Longitudinal sealed underwater optical cable and preparation method thereof - Google Patents

Abstract

The invention discloses a longitudinal sealed underwater optical cable which comprises optical units, a reinforcing device and a waterproof sheath, wherein water-blocking and anti-corrosion materials are filled in gaps among the optical units, the reinforcing device and the waterproof sheath, the reinforcing device comprises a central line and an inter-optical-unit reinforcing device, the inter-optical-unit reinforcing device comprises a plurality of reinforcing pieces with circular cross sections, the optical units and the plurality of reinforcing pieces with circular cross sections are tightly arranged around the central line in a concentric circle mode, and the water-blocking and anti-corrosion materials are solid at normal temperature. By adopting the technical scheme, the light units are distributed in the middle of the reinforcing piece, so that the high side pressure resistance and water leakage resistance effects are generated. The cable has the advantages of simple structure, small diameter, good longitudinal water tightness, good corrosion resistance, tensile resistance, pressure resistance and the like, improves the product quality and reliability of the underwater optical cable, and reduces the manufacturing cost of the optical cable. The invention also discloses a manufacturing method of the optical cable.

Description

Longitudinal sealed underwater optical cable and preparation method thereof

technical field

The invention relates to a device for preparing a longitudinally sealed underwater optical cable, in particular to a rotary mold, which belongs to the technical field of optical fiber communication, monitoring signal transmission or temperature measurement system.

Background technique

Underwater optical cables are mainly used in underwater environmental conditions in rivers, lakes, shallow seas, coastal areas, islands and other areas. The underwater optical cable is suitable for working underwater all year round and needs to meet certain conditions, such as: good moisture resistance and corrosion resistance and good compression resistance.

The structure of the underwater optical cable in the prior art is mainly composed of an optical unit, a strengthening member and a sheath. The optical unit is a structure that provides certain protection for the optical fiber. Usually, underwater optical cables use metal or plastic lining tubes in the optical cable structure to protect the optical unit from corrosion and improve strength. For example, in recent years, stainless steel The tube-type light unit is widely used because of its good corrosion resistance, good pressure resistance, and small diameter. The strengthening method is to wrap multi-layer reinforcements with circular cross-sections, steel tape armor, etc. around the optical unit and the metal or plastic inner liner, which are used to resist the lateral pressure and tensile strength of the optical cable during use. Force, etc., the main watertight material of the optical cable is between the optical unit and the strengthening member outside the protection tube. In addition, the gap inside the optical cable is filled with water-blocking and anti-corrosion materials. Usually, viscous filling materials such as asphalt and water-blocking cable paste are used. Once the sheath of the optical cable is damaged by external force or biology, the water is easily damaged by excessive pressure. Large enters the interior of the cable and breaks through the viscous filling material to deform it and create a partial gap to continue to infiltrate. The underwater optical cable in the prior art has defects such as high manufacturing cost, complex structure, large cable diameter, and poor longitudinal watertightness.

In addition, in the prior art, the filling of commonly used viscous filling materials such as asphalt and water-blocking cable paste is realized by immersing the corresponding viscous filling materials after the cables are stranded. However, it is still difficult to fill all the gaps inside the cable with the filling material, thus affecting the watertight performance.

Contents of the invention

The technical problem to be solved by the present invention is to provide an optical cable by overcoming the defects of the existing underwater optical cable such as complex structure, high manufacturing cost, large cable diameter, and poor longitudinal watertightness.

In order to achieve the above object, the technical scheme adopted in the present invention is:

The optical cable includes an optical unit, a strengthening device and a waterproof sheath, and the gap between the optical unit, the strengthening device and the waterproof sheath is filled with water-blocking and anti-corrosion materials. The reinforcing device, the reinforcing device between the light units includes several reinforcing pieces with a circular cross section, and the optical unit and the several reinforcing pieces with a circular cross section are closely placed around the center line in a concentric circle.

By adopting the above-mentioned technical scheme, the present invention has achieved the following beneficial effects relative to the prior art:

The light units are distributed in the middle of the stiffeners, resulting in a high resistance to lateral pressure. Such an optical cable has a simple structure, a small cable diameter, good longitudinal water tightness, and has good performance advantages such as corrosion resistance, tensile strength and pressure resistance, which improves the product quality and reliability of underwater optical cables and reduces the cost of manufacturing optical cables. cost.

The further technical problem to be solved by the present invention is to provide a method for manufacturing an optical cable capable of forming a fully filled structure and producing good longitudinal watertight performance.

In order to achieve the above object, the technical scheme adopted in the present invention is:

The manufacturing method of optical cable is characterized in that comprising the following steps:

(1) Melting water-blocking and anti-corrosion materials and maintaining a constant temperature;

(2) Pass the core wire of the cable to be twisted through the threading hole of the rotary threading die of the rotary mould, and contact the melted water-blocking and anti-corrosion material in the cavity of the rotary mould;

(3) Take a reinforcing member with a circular cross-section as the axis and twist other reinforcing members with a circular cross-section and the optical unit synchronously around it, so that the optical unit and other reinforcing members with a circular cross-section are closely placed in the around the circular cross-section of the axis, during the stranding process, the light unit and other circular cross-section reinforcements are moved along the axis of the circular cross-section while simultaneously Rotate along a stiffener with a circular cross-section as the axis;

(4) cooling and curing;

(5) Cover the outer side of the cable with a waterproof sheath.

By adopting the above-mentioned technical scheme, the present invention has achieved the following beneficial effects relative to the prior art:

The filling of twisted cables, water-blocking and anti-corrosion materials is carried out during the dynamic process of heating, melting and rotation, so that the internal space of the optical cable can be completely filled with water-blocking and anti-corrosion materials, and can be easily connected with all components inside the cable. Good bonding, a very good fully sealed structure is formed inside the optical cable; and the water-blocking and anti-corrosion material is solid when cooled to room temperature, and it is difficult to deform under water pressure, which has a good pressure-bearing and water-blocking effect; The waterproof sheath on the outside of the cable also includes a water-blocking wrapping tape and an outer sheath, so that the optical cable forms a solid, fully-filled sealing structure as a whole, resulting in good longitudinal watertight performance.

Description of drawings

The specific embodiment of the present invention will be further described below in conjunction with accompanying drawing, wherein:

Fig. 1 is the schematic cross-sectional view of the optical cable prepared by the preferred embodiment of the preparation method of longitudinally sealed underwater optical cable of the present invention;

Fig. 2 is a partially enlarged view of the light unit of the embodiment shown in Fig. 1;

Fig. 3 is the structural representation of the preferred embodiment of rotary mold of the present invention;

Fig. 4 is a structural schematic view of the panel of the rotary threading die of the embodiment shown in Fig. 3 .

Detailed ways

Figures 1 to 2 show the optical cable prepared by the preferred embodiment of the method for preparing a longitudinally sealed underwater optical cable of the present invention.

As shown in FIG. 1 , the optical cable includes an optical unit 4 , a strengthening device 5 , a wrapping tape 7 and an outer sheath 8 . The reinforcing device 5 includes a central line 51, a reinforcing device 52 between optical units and a layer of external reinforcing device 53 for the optical unit: the central line 51 is a reinforcing member with a circular cross section, and the reinforcing device 52 between optical units includes five A reinforcing member with a circular cross-section, the light unit 4 and the five reinforcing members with a circular cross-section are closely placed around the center line 51 in a concentric circle; the external strengthening device 53 of the light unit includes 12 reinforcing members with a The circular reinforcing piece is placed closely outside the optical unit 4 and the reinforcing device 52 between the optical units. It should be noted that the external strengthening device 53 of the light unit is not necessary, and the number of layers can also be multiple layers, which can be arranged according to requirements. In addition, a better embodiment of the reinforcing member with a circular cross section is galvanized steel wire, medium carbon steel wire with alloy coating, aluminum-clad steel wire, FRP or kFRP.

The waterproof sheath includes a water-blocking sheath coated on the outside of the cable by a watertight material, specifically including a wrapping tape 7 and an outer sheath 8 . As a more preferred example: the material of the outer sheath 8 is plastic or rubber-plastic elastomer material; the material of the wrapping tape 7 is a water blocking tape or a plastic film, more preferably a plastic film. When the plastic film is extruded into the outer sheath, the residual temperature of the extruded material after extrusion heating is bonded with the outer sheath 8 .

The gap between the light unit 4 , the reinforcing device 5 and the wrapping tape 7 is filled with a water-blocking and anti-corrosion material 6 . The water-blocking and anti-corrosion material 6 is hot melt adhesive.

In addition, an optimization can also be proposed for the optical unit 4. Referring to FIG. In the tube 3 , hydrogen-absorbing fiber paste 2 is filled in the gap in the stainless steel tube 3 . However, in this embodiment, the number of optical units 4 in the optical cable may be one or more, and a more preferred example is 1-3.

The preparation method of optical cable is described in detail below by embodiment 1:

Example 1:

Fiber optic cable contains:

2 optical units 4, each optical unit 4 contains: 24 optical fibers 1, hydrogen-absorbing fiber paste 2, stainless steel tube 3 with a diameter of 3 mm;

The middle line 51 is: a steel wire with a diameter of 3mm;

The strengthening device 52 between optical units includes: 4 steel wires with a diameter of 3 mm;

The external strengthening device 53 of the light unit includes: 12 steel wires with a diameter of 3mm;

The water-blocking and anti-corrosion material 6 is made of hot melt adhesive;

The waterproof sheath includes: wrapping tape 7, polyurethane sheath 8.

The preparation method comprises the following steps:

The first step is to wrap the optical fiber 1 and the hydrogen-absorbing fiber paste 2 inside the stainless steel tube 3 by conventional techniques to make the optical unit 4 .

The second step is to melt the hot melt adhesive and keep it at a constant temperature;

The third step is to contact the 5 steel wires and 2 light units with the molten hot melt adhesive in the rotating mold;

The fourth step is to twist the other 4 steel wires and 2 light units synchronously around it with a steel wire as the axis, so that the other 4 steel wires and 2 light units are closely placed around the steel wire as the axis , during the stranding process, make the other 4 steel wires and 2 light units rotate along the steel wire of the axis while advancing along the steel wire of the axis;

The fifth step is to cool down to make the hot melt adhesive solidify;

The sixth step, repeat the second step to the fifth step, the difference is that the cable cured in the fifth step is used as the axis, and 12 steel wires are tightly placed around it;

The seventh step is to wrap a layer of wrapping tape on the outermost side of the cable;

The eighth step, squeeze the outer sheath.

Some preferences are proposed for the preparation method described in Example 1: for example, in the second step, the melting and constant temperature temperature is 70-150°C; for example, between the sixth step and the seventh step, there is also a sizing die hole to scrape off the surface of the cable The step of excess hot melt adhesive; another example is to use air cooling and cooling to solidify in the fifth step. These preferred methods can all improve the product quality and reliability of the optical cable.

With such a preparation method, the hot melt adhesive can be well bonded to all components inside the cable and fill all the gaps, and the inner side of the outer sheath is also made of watertight structure and materials, so that the optical cable forms a solid full-filled sealing structure , resulting in very good longitudinal watertightness. At the same time, the optical cable obtained by the preparation method has a simple structure, a small cable diameter, and has performance advantages such as corrosion resistance, tension resistance and pressure resistance, improves the product quality and reliability of the optical cable, and reduces the manufacturing cost of the underwater optical cable.

Figures 3-4 show a preferred embodiment of the rotary mold of the present invention. As shown in Figure 3, the rotary die of the present embodiment includes a rotary threading die 11 and a sizing die 21; the sizing die 21 includes a coaxial and through bell mouth and a sizing die hole 23; the rotary threading die The outside of 11 is at the same angle as the bell mouth of the sizing die 21, so that the rotary threading die 11 can be tightly fitted in the bell mouth of the sizing die 21 and can be rotated, and the rotating threading die 11 is closely fitted in the bell mouth of the sizing die 21 At this time, a cavity 25 is formed between the rotating threading die 11 and the sizing die 21; meanwhile, the threading hole 12 is also included in the rotating threading die 11. The threading hole 12 includes a central threading hole 121 and several side threading holes 122, the central threading hole 121 is coaxial with the sizing die hole 23, and the several side threading holes 122 are distributed in the center in the form of concentric circles Around the threading hole 121 (see Fig. 4) and the angle between the several side threading holes 122 and the center threading hole 121 is the same; 22 is connected with the cavity 25 formed between the rotary threading die 11 and the sizing die 21.

As a preferred mode of this embodiment, the feed hole 22 is connected with a constant temperature heating device 24 .

As another preferred mode of this embodiment, conventional heating, constant temperature and heat preservation devices are placed outside the sizing die 21 .

The rotary mold of this embodiment will be further described in conjunction with Example 2 below.

Example 2:

Fiber optic cable contains:

1 optical unit 4, each optical unit 1 contains: 12 optical fibers 1, hydrogen-absorbing fiber paste 2, stainless steel tube 3 with a diameter of 2.8 mm;

The middle line 51 is: a steel wire with a diameter of 2.8mm;

The strengthening device 52 between optical units includes: 5 steel wires with a diameter of 2.8mm;

The water-blocking and anti-corrosion material 6 is made of hot melt adhesive;

The waterproof sheath includes: wrapping tape 7, polyethylene sheath 8.

Repeat the preparation method of Embodiment 1 in combination with the rotating mold, except that there is no external reinforcing device 53 for the light unit in this embodiment, so the sixth step above is omitted. The preparation method comprises the following steps:

The first step is to prefabricate the light unit;

In the second step, the hot melt adhesive is melted in the constant temperature heating device 24, and the melted hot melt adhesive enters the cavity 25 of the rotary mold through the feed hole 22;

The third step is to pass through the light unit and the steel wire, pass through the threading hole 12 of the rotary threading mold 11, enter the inner cavity 25 of the rotary mold, and contact the molten hot melt adhesive. Wherein, a steel wire enters the central threading hole 121 , and other steel wires and light units enter the side threading hole 122 . When the stranding machine rotates, it drives the rotating threading die 11 to rotate synchronously, and the optical unit and steel wire are twisted into a cable core at the bell mouth of the sizing die 21 and the sizing die hole 23; in the inner cavity 25 of the rotating die, the optical unit and steel wire The steel wire rotates along the central axis while moving forward along the oblique direction of the bell mouth and the central axis, driving the hot melt adhesive to be coated on the surface of the light unit and each steel wire, so that the outer surface of the cable and all internal gaps are filled with hot melt adhesive , and the excess hot melt adhesive is included in the cavity 25 of the rotary mold when the cable passes through the sizing die hole 23 and continues to be used.

Step 4: After the cable fully filled and sealed by the hot melt adhesive goes out of the sizing die hole 23, it is cooled by air while moving forward, and the hot melt adhesive is gradually solidified.

Step 5: Wrap one layer of wrapping tape 7 around the outer side of the cable.

The sixth step, extruding the outer sheath 8.

When using the rotary mold to implement the preparation method of the present invention, the tight fit of the rotary threading mold 11 and the bell mouth of the sizing mold 21 also makes the rotary threading mold 11 rotate in the bell mouth of the sizing mold 21, and simultaneously play a role in sealing the hot melt adhesive. Outflow cavity 25 of the rotating mold acts.

In addition, the preferred thickness range of the rotary threading die 11 is 10-50mm.

The present invention has been described in detail above in conjunction with the accompanying drawings and specific embodiments, but the present invention is not limited thereto. Any person skilled in the art can, within the scope of their knowledge and without violating the purpose of the present invention, Make various changes and modifications to it.

Claims (7)

1. An optical cable, comprising an optical unit, a strengthening device and a waterproof sheath, the gap between the optical unit, the strengthening device and the waterproof sheath is filled with water-blocking and anti-corrosion materials, characterized in that: the strengthening device includes 1 reinforcing device between the midline and the optical unit, the reinforcing device between the optical units includes 5 reinforcing members with a circular cross section, and the 1 optical unit and the 5 reinforcing members with a circular cross section are arranged in a concentric circle Closely placed around the midline, the light unit strengthening device also includes an external light unit strengthening device, and the light unit external strengthening device includes one or several layers of closely arranged circular cross-sections closely placed on the outside of the light unit strengthening device reinforcements. 2. The optical cable according to claim 1, wherein the waterproof sheath comprises a wrapping tape and an outer sheath, the wrapping tape is wrapped around the outside of the optical unit strengthening device, and the outer sheath wraps Overlay on the outside of the wrapping tape. 3. The optical cable according to claim 2, characterized in that: the material of the outer sheath is plastic or rubber-plastic elastomer material. 4. The optical cable according to claim 2, characterized in that: the wrapping tape is made of water blocking tape or plastic film. 5. The optical cable according to claim 1, characterized in that: the central line and the reinforcing member with a circular cross section are galvanized steel wires, alloy-coated medium carbon steel wires, aluminum-clad steel wires, FRP or kFRP. 6. The optical cable according to claim 1, characterized in that: the optical unit is a stainless steel tube type optical unit, which includes a stainless steel tube and several optical fibers, and the several optical fibers are coated in the stainless steel tube, and inside the stainless steel tube The gaps are filled with hydrogen-absorbing fiber paste. 7. The optical cable according to claim 1, wherein the water-blocking and anti-corrosion material is hot melt adhesive.

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