CN111370157A - Heat-resistant and waterproof insulated cable and preparation method thereof - Google Patents

Abstract

The invention discloses a heat-resistant and waterproof insulated cable and a preparation method thereof. Five sector-shaped tinned copper wire conductors are symmetrically arranged around a galvanized steel wire conductor to form an inner conductor, and the outer part of the inner conductor is sequentially coated with UV curing Unsaturated polyester resin layer, fluororubber inner moisture-proof layer, silane-grafted cross-linked low-density polyethylene inner insulating layer, ETFE outer insulating layer, fluorine rubber outer moisture-proof layer, polypropylene moisture-absorbing layer, shielding mesh conductor layer, PTFE winding Tape layer, double polyethylene water blocking layer, inner sheath, heat resistant layer and outer sheath. Insulated cables have excellent heat resistance, moisture-proof and waterproof performance and electrical shielding properties, better adaptability to the laying environment, and improve the safety and reliability of cables.

Description

Heat-resistant and waterproof insulated cable and preparation method thereof

technical field

The invention relates to the technical field of cables, in particular to a heat-resistant and waterproof insulated cable and a preparation method thereof.

Background technique

A large number of cables are used in electric power construction, and the cable insulation performance is good, which can not only improve the reliability of power supply, but also beautify the city appearance, and has higher promotion and application value. In the process of cable construction, the phenomenon that the cable is damp and water enters from time to time, which becomes a potential hidden danger that affects the safe operation of the cable. When the cable is laid, it often crosses roads, bridges, etc. Due to climate and other reasons, it is inevitable that moisture will penetrate into the cable. Under the action of the electric field, water tree aging will occur, the cable insulation will be damaged, and finally lead to cable breakdown accidents. If you just increase the thickness of the cable insulation to delay the aging phenomenon of water trees, it will not cure the symptoms.

SUMMARY OF THE INVENTION

Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a heat-resistant and waterproof insulated cable, which has both excellent heat resistance, moisture-proof and waterproof performance and electrical shielding properties, better adaptability to the laying environment, and improved The safety and reliability of the cable. At the same time, a preparation method of a heat-resistant and waterproof insulated cable is also provided.

The present invention solves the above-mentioned technical problems through the following technical solutions.

Heat-resistant and waterproof insulated cable, five fan-shaped tinned copper wire conductors are symmetrically arranged around a galvanized steel wire conductor to form an inner conductor. Moisture-proof layer, silane-grafted cross-linked low-density polyethylene inner insulating layer, ETFE outer insulating layer, fluorine rubber outer moisture-proof layer, polypropylene moisture-absorbing layer, shielding mesh conductor layer, PTFE wrapping tape layer, double-layer polyethylene water blocking layer layer, inner sheath, heat resistant layer and outer sheath.

Preferably, the galvanized steel wire conductor is a galvanized steel single wire or a galvanized steel strand.

Preferably, the fan-shaped tinned copper wire conductor is composed of a plurality of tinned copper stranded wires that are twisted together and compressed into a fan-shaped structure, and the tinned copper stranded wires are composed of a plurality of tinned copper single wire bundles.

Preferably, the thickness of the silane-grafted cross-linked low-density polyethylene inner insulating layer is greater than the thickness of the ETFE outer insulating layer.

Preferably, the thickness of the ETFE outer insulating layer is one-quarter to one-half of the thickness of the silane-grafted cross-linked low-density polyethylene inner insulating layer.

Preferably, the polypropylene moisture-absorbing layer is a unidirectional spiral overlapping wrapping of polypropylene wrapping tape on the fluororubber outer moisture-proof layer.

Preferably, the shielded mesh conductor layer is composed of copper stranded wires of different wire diameters that are twisted and braided in opposite directions, and the copper stranded wires are composed of a stainless steel monofilament central reinforcing wire and a number of tinned copper monofilaments concentrically twisted. In the structure, the diameter of the stainless steel monofilament is 0.05mm to 0.5mm, and the diameter of the tinned copper monofilament is 0.05mm to 0.6mm.

Preferably, the double-layer polyethylene water-blocking layer is co-extruded from the inner MDPE water-blocking layer on the inner side and the LDPE water-blocking outer layer on the outer side.

Preferably, the inner sheath and the outer sheath are both neoprene sheaths, and the heat-resistant layer is made of chlorinated polyethylene.

The preparation method of the heat-resistant and waterproof insulated cable, the specific steps are as follows:

Step 1: Obtain the inner conductor through the twisting process;

Step 2: coating an unsaturated polyester resin layer on the inner conductor through a dipping process and performing UV curing treatment to form a UV curing unsaturated polyester resin layer;

Step 3: forming an inner moisture-proof layer of fluororubber on the UV-cured unsaturated polyester resin layer through an extrusion process;

Step 4: form a silane graft cross-linked low density polyethylene inner insulating layer on the inner moisture-proof layer of fluororubber by extrusion and cross-linking process; Step 5: insulate the silane graft cross-linked low density polyethylene inner insulation by extrusion process An ETFE outer insulating layer is formed on the layer, and a gap is maintained between the ETFE outer insulating layer and the silane-grafted cross-linked low-density polyethylene inner insulating layer;

Step 6: Form the outer moisture-proof layer of fluororubber on the outer insulating layer of ETFE through the extrusion process;

Step 7: Wrap the polypropylene moisture absorption layer, the shielding mesh conductor layer and the PTFE wrapping tape layer on the ETFE outer insulating layer in turn through the winding process;

Step 8: An inner sheath, a heat-resistant layer and an outer sheath are sequentially formed on the PTFE wrapping tape layer by an extrusion process to prepare an insulated cable.

Beneficial effects of the present invention:

1. The UV-cured unsaturated polyester resin layer has high hardness and good heat resistance. The UV-cured unsaturated polyester resin is not easy to expand and shrink with the change of cable temperature, and it will not easily occur between the inner conductor and the inner moisture-proof layer of the fluororubber. interlayer peeling. The inner moisture-proof layer of fluorine rubber and the outer moisture-proof layer of fluorine rubber have excellent moisture-proof and water-blocking properties. It can further diffuse the water to the insulating layer, thereby effectively delaying the water tree aging phenomenon of the insulating layer. It has excellent electrical insulation properties, better voltage resistance, extended cable life, and durable use.

2. The linear expansion coefficient of the galvanized steel wire conductor is smaller than that of the fan-shaped tinned copper wire conductor, and the extension of the fan-shaped tinned copper wire conductor is greater than that of the galvanized steel wire conductor, so as to balance and absorb the extension of the cable and restrain the extension force of the cable end , improve the adaptability of the laying environment.

3. The outside of the cable adopts a three-layer bonding body of neoprene inner sheath with high toughness, high strength and high wear resistance, chlorinated polyethylene heat-resistant layer and neoprene outer sheath, which has high mechanical strength and can effectively reduce The phenomenon of sheath cracking, adding a chlorinated polyethylene heat-resistant layer between the neoprene inner sheath and the neoprene outer sheath is not only beneficial to improve the bonding performance, but also increases the heat resistance.

4. The polypropylene moisture-absorbing layer is a polypropylene winding tape, which is wrapped in a unidirectional spiral and overlapping on the outer moisture-proof layer of the fluororubber. The potential difference between the outer moisture-proof layer and the shielding mesh conductor layer reduces the uneven electric field intensity and the occurrence of partial discharge.

5. The shielding mesh conductor layer is composed of copper stranded wires of different wire diameters that are twisted and braided against each other, which can effectively reduce the braiding gap and greatly reduce the friction between tinned copper monofilaments, thereby improving noise shielding. characteristics, and make the cable have better flexibility. The copper stranded wire is composed of a stainless steel monofilament central reinforcing wire and several tinned copper monofilaments concentrically twisted. The stainless steel monofilament central reinforcing wire improves the mechanical strength of the copper stranded wire, and the tinned copper monofilament has excellent bending resistance. The shielding layer formed by the copper stranded wire braided by the two is not prone to breakage, which greatly improves the durability of the cable.

6. The shielding mesh conductor layer can effectively suppress the leakage of internal signals or noise to the outside and suppress the interference from external signals. The PTFE wrapping tape layer has a small friction coefficient, reduces the stress concentration of the shielding mesh conductor layer, and improves the enhanced shielding characteristics. The stability, to ensure effective shielding performance, durable use.

7. The fan-shaped tinned copper wire conductor is composed of several tinned copper stranded wires and compacted into a fan-shaped structure. The tinned copper stranded wire is composed of several tinned copper monofilament bundles, which is beneficial to reduce the Torsional stress, restraining single wire deformation, and improving the tensile strength and stability of fan-shaped tinned copper wire conductors.

Description of drawings

FIG. 1 is a schematic cross-sectional structure diagram of a specific embodiment of the present application.

In the picture: 1- Galvanized steel wire conductor, 2- Sector tinned copper wire conductor, 3- UV curing unsaturated polyester resin layer, 4- Fluorine rubber inner moisture-proof layer, 5- Silane graft cross-linked low density polyethylene inner layer Insulation layer, 6-ETFE outer insulation layer, 7-Fluoroelastomer outer moisture-proof layer, 8-Polypropylene moisture absorption layer, 9-Shield mesh conductor layer, 10-PTFE wrapping tape layer, 11-Double polyethylene water blocking layer , 12-inner sheath, 13-heat-resistant layer, 14-outer sheath.

Detailed ways

The technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments.

As shown in FIG. 1 , in the heat-resistant and waterproof insulated cable of the embodiment of the present invention, five fan-shaped tinned copper wire conductors 2 are symmetrically arranged around a galvanized steel wire conductor 1 to form an inner conductor, wherein the galvanized steel wire conductor 1 It can be galvanized steel monofilament or galvanized steel strand. The fan-shaped tinned copper wire conductor 2 is composed of a plurality of tinned copper stranded wires that are twisted together and compressed into a fan-shaped structure.

The outer part of the inner conductor is sequentially coated with a UV-curable unsaturated polyester resin layer 3, a fluororubber inner moisture-proof layer 4, a silane-grafted cross-linked low-density polyethylene inner insulating layer 5, an ETFE outer insulating layer 6, and a fluororubber outer moisture-proof layer. layer 7 , polypropylene moisture absorption layer 8 , shielding mesh conductor layer 9 , PTFE wrapping tape layer 10 , double polyethylene water blocking layer 11 , inner sheath 12 , heat-resistant layer 13 and outer sheath 14 . The thickness of the silane-grafted and cross-linked low-density polyethylene inner insulating layer 5 is greater than the thickness of the ETFE outer insulating layer 6. Preferably, the ETFE outer insulating layer 6 is as thick as the silane-grafted and cross-linked low-density polyethylene. One-quarter to one-half the thickness of the insulating layer 5 . In one embodiment, the polypropylene moisture-absorbing layer 8 is a polypropylene winding tape unidirectionally spirally overlapped and wrapped on the fluororubber outer moisture-proof layer 7 . In one embodiment, the shielding mesh conductor layer 9 is composed of copper stranded wires of different wire diameters that are twisted and braided in a reverse spiral. The single wire is concentrically twisted, the diameter of the stainless steel single wire is 0.05mm to 0.5mm, and the diameter of the tinned copper single wire is 0.05mm to 0.6mm. In one embodiment, the double-layer polyethylene water-blocking layer 11 is formed by co-extrusion of the inner MDPE water-blocking layer on the inner side and the LDPE water-blocking outer layer on the outer side. The inner sheath 12 and the outer sheath 14 are made of neoprene, for example, and the heat-resistant layer 13 is made of chlorinated polyethylene.

The preparation method of the heat-resistant and waterproof insulated cable, the specific steps are as follows:

Step 1: Obtain the inner conductor through the twisting process;

Step 2: coating an unsaturated polyester resin layer on the inner conductor through a dipping process and performing UV curing treatment to form a UV curing unsaturated polyester resin layer;

Step 3: forming an inner moisture-proof layer of fluororubber on the UV-cured unsaturated polyester resin layer through an extrusion process;

Step 4: form a silane graft cross-linked low density polyethylene inner insulating layer on the inner moisture-proof layer of fluororubber by extrusion and cross-linking process; Step 5: insulate the silane graft cross-linked low density polyethylene inner insulation by extrusion process An ETFE outer insulating layer is formed on the layer, and a gap is maintained between the ETFE outer insulating layer and the silane-grafted cross-linked low-density polyethylene inner insulating layer;

Step 6: Form the outer moisture-proof layer of fluororubber on the outer insulating layer of ETFE through the extrusion process;

Step 7: Wrap the polypropylene moisture absorption layer, the shielding mesh conductor layer and the PTFE wrapping tape layer on the ETFE outer insulating layer in turn through the winding process;

Step 8: An inner sheath, a heat-resistant layer and an outer sheath are sequentially formed on the PTFE wrapping tape layer through an extrusion process to prepare an insulated cable.

The present invention is described through the embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, in accordance with the teachings of the present invention, these features and embodiments may be modified to adapt a particular situation and material without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the claims of the present application belong to the protection scope of the present invention.

Claims (10)

1. A heat-resistant and waterproof insulated cable, characterized in that: five fan-shaped tinned copper wire conductors (2) are symmetrically arranged around a galvanized steel wire conductor (1) to form an inner conductor, and the outside of the inner conductor is sequentially coated with UV-curable unsaturated polyester resin layer (3), fluororubber inner moisture-proof layer (4), silane-grafted cross-linked low-density polyethylene inner insulating layer (5), ETFE outer insulating layer (6), fluorine rubber outer moisture-proof layer (7), polypropylene moisture-absorbing layer (8), shielding mesh conductor layer (9), PTFE wrapping tape layer (10), double-layer polyethylene water-blocking layer (11), inner sheath (12), heat-resistant layer (13) and outer sheath (14). 2. The heat-resistant and waterproof insulated cable according to claim 1, wherein the galvanized steel wire conductor (1) is a galvanized steel single wire or a galvanized steel strand. 3. The heat-resistant and waterproof insulated cable according to claim 1, wherein the fan-shaped tinned copper wire conductor (2) is composed of a plurality of tinned copper stranded wires that are twisted together and compressed into a fan-shaped structure. The tinned copper stranded wire consists of several tinned copper monofilament bundles. 4. The heat-resistant and waterproof insulated cable according to claim 1, wherein the thickness of the silane-grafted cross-linked low-density polyethylene inner insulating layer (5) is greater than the thickness of the ETFE outer insulating layer (6). 5. The heat-resistant and waterproof insulated cable according to claim 4, wherein the thickness of the ETFE outer insulating layer (6) is equal to the thickness of the silane-grafted cross-linked low-density polyethylene inner insulating layer (5) thickness. quarter to half. 6. The heat-resistant and waterproof insulated cable according to claim 1, characterized in that: the polypropylene moisture-absorbing layer (8) is a polypropylene winding tape unidirectionally spirally overlapped and wrapped around the fluororubber outer moisture-proof layer (7). )superior. 7 . The heat-resistant and waterproof insulated cable according to claim 1 , wherein the shielded mesh conductor layer (9) is composed of copper stranded wires of different wire diameters that are twisted and braided in opposite directions. The wire consists of a stainless steel monofilament central reinforcing wire and several tinned copper monofilaments concentrically twisted. 8. The heat-resistant and waterproof insulated cable according to claim 1, wherein the double-layer polyethylene water-blocking layer (11) is co-extruded by the MDPE water-blocking inner layer on the inner side and the LDPE water-blocking outer layer on the outer side. forming. 9. The heat-resistant and waterproof insulated cable according to claim 1, wherein the inner sheath (12) and the outer sheath (14) are both neoprene sheaths, and the heat-resistant layer (13) is made of chlorinated polyethylene. 10. The preparation method of heat-resistant and waterproof insulated cable, characterized in that: the specific steps are as follows: Step 1: Obtain the inner conductor through the twisting process; Step 2: coating an unsaturated polyester resin layer on the inner conductor through a dipping process and performing UV curing treatment to form a UV curing unsaturated polyester resin layer; Step 3: forming an inner moisture-proof layer of fluororubber on the UV-cured unsaturated polyester resin layer through an extrusion process; Step 4: form a silane graft cross-linked low density polyethylene inner insulating layer on the inner moisture-proof layer of fluororubber by extrusion and cross-linking process; Step 5: insulate the silane graft cross-linked low density polyethylene inner insulation by extrusion process An ETFE outer insulating layer is formed on the layer, and a gap is maintained between the ETFE outer insulating layer and the silane-grafted cross-linked low-density polyethylene inner insulating layer; Step 6: Form the outer moisture-proof layer of fluororubber on the outer insulating layer of ETFE through the extrusion process; Step 7: Wrap the polypropylene moisture absorption layer, the shielding mesh conductor layer and the PTFE wrapping tape layer on the ETFE outer insulating layer in turn through the winding process; Step 8: An inner sheath, a heat-resistant layer and an outer sheath are sequentially formed on the PTFE wrapping tape layer by an extrusion process to prepare an insulated cable.

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