High-flame-retardant zero-dripping low-smoke halogen-free photoelectric composite cable for ships and maritime work platforms

Abstract

The invention relates to a high-flame-retardant zero-dripping low-smoke halogen-free photoelectric composite cable for ships and maritime work platforms. The high-flame-retardant zero-dripping low-smoke halogen-free photoelectric composite cable sequentially comprises an electric unit, at least one optical fiber unit, an inner protective layer, an armor layer and an outer protective layer from inside to outside. The outer surface of the electric unit, the outer surface of the optical fiber unit, the inner protective layer and the outer protective layer are all prepared from a flame-retardant sheath material; the flame-retardant sheath material comprises the following components in percentage by mass: 15-35% of EVA (Ethylene Vinyl Acetate); 1%-10% of EPD M; 1% to 10% of LDPE; 1% to 10% of HDPE; 1%-10% of a compatilizer; 0.1%-0.5% of an antioxidant; 20%-50% of an inorganic flame retardant; 5%-10% of a charring agent; the charring agent is prepared by mixing montmorillonite, red phosphorus and melamine cyanurate according to a ratio of 2: 1: 1. The photoelectric composite cable designed by the invention has the characteristics of high flame retardance, low smoke and zero dripping during combustion, no halogen, UV resistance, hydrolysis resistance and the like.

Description

Technical Field

[0001] The invention relates to the technical field of optoelectronic composite cables, and in particular to a highly flame-retardant, zero-drip, low-smoke, halogen-free optoelectronic composite cable for ships and offshore platforms. Background Art

[0002] Flame-retardant cables refer to cables whose flames spread only within a limited range after the fire source is removed, and the residual flames or residual burnings extinguish themselves within a limited time. Due to the large differences in the flame retardancy of low-smoke halogen-free polyolefin materials with different performances, the performance of cables such as smoke toxicity, dripping, and heat release varies greatly. Internationally, the EU EN 13501-6 "Fire protection classification of building products and buildings-Part 6: Classification of cable protection test data" standard divides the flame retardant performance of cables into seven levels: Aca, B1ca, B2ca, Cca, Dca, Eca, and Fca, based on multiple indicators such as the calorific value of combustion, flame spread, peak heat release rate, and combustion growth rate index of cable products. In addition, on this basis, additional performance levels are identified based on the three indicators of burning dripping / particles (d), smoke generation level (s), and corrosiveness (a) in the combustion test. The domestic GB31247 "Classification of Combustion Performance of Cables and Optical Cables" also divides the flame retardant performance of cables into four levels: A, B1, B2, and B3, based on multiple indicators such as combustion calorific value, flame spread, peak heat release rate, and smoke production rate index. In addition, on this basis, additional performance levels are identified based on three indicators in the combustion test: burning drips / particles (d), smoke toxicity level (t), and corrosiveness (a). Therefore, the research and development significance of zero-drip B1-level high flame retardant cables is in line with the current international expectations for flame retardant cables.

[0003] Existing technologies all use low-smoke, halogen-free, highly flame-retardant sheath materials to reduce the combustible content of the materials, thereby reducing the total heat release and smoke release of the cable. However, the traditional flame-retardant sheath formula can only ensure that the heat release performance of the cable does not exceed the standard, but cannot ensure that the sheath or other structures will not fall off during combustion. Therefore, in the event of a fire, the burning and falling materials of the cable may ignite other items, causing the fire to expand.

[0004] The optoelectronic composite cable for ships and offshore platforms is a special cable for supporting the propulsion system of military ships, and is also a special cable for amphibious combat ships, medical ships and other projects. The use environment of this cable is complex and harsh, and the outer sheath of the cable needs to have excellent high flame retardant properties. At the same time, it also needs to meet the requirements of low smoke, halogen-free, low toxicity, UV resistance, and long service life during combustion. Therefore, it is an urgent problem to design a highly flame retardant, zero-drip, low-smoke, halogen-free optoelectronic composite cable for ships and offshore platforms. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, the present invention provides an optoelectronic composite cable for ships and offshore platforms, which has good flame retardancy, zero dripping after combustion, and low smoke and halogen-free during combustion.

[0006] In the first aspect, the present application provides a highly flame-retardant zero-drip low-smoke halogen-free optoelectronic composite cable for ships and offshore platforms, which includes, from the inside to the outside, an electrical unit, at least one optical fiber unit, an inner sheath, an armor layer, and an outer sheath. The outer surface of the electrical unit, the outer surface of the optical fiber unit, the inner sheath, and the outer sheath are all made of a flame-retardant sheath material, and the flame-retardant sheath material includes the following components by mass percentage:

[0007]

[0008] The carbon-forming agent is composed of montmorillonite, red phosphorus and melamine cyanurate mixed in a mass ratio of 2:1:1, and the inorganic flame retardant includes magnesium hydroxide and aluminum hydroxide, wherein the magnesium hydroxide accounts for 10% to 40% of the total formula content, and the aluminum hydroxide accounts for 10% to 40% of the total formula content.

[0009] More specifically, the content of the carbon-forming agent is 2% to 4.5%.

[0010] More specifically, the magnesium hydroxide accounts for 15% to 25% of the total formula content, and the aluminum hydroxide accounts for 15% to 25% of the total formula content.

[0011] More specifically, the compatibilizer is maleic anhydride grafted ethylene vinyl acetate.

[0012] More specifically, the antioxidant is a hindered phenol antioxidant.

[0013] More specifically, a first glass fiber tape layer is arranged on a surface of the inner protective layer away from the armor layer, and a second glass fiber tape layer is arranged on a surface of the outer protective layer close to the armor layer.

[0014] More specifically, the armor layer is made of galvanized steel wire braiding.

[0015] In a second aspect, the present application provides a method for preparing a highly flame-retardant, zero-drip, low-smoke, halogen-free optical fiber composite cable for ships and offshore platforms, comprising the following steps:

[0016] S1. Prepare an electrical unit by twisting at least two cables, filling a rock wool rope in the twisted gap, wrapping a polyester tape around the outer surface after twisting, and arranging a flame retardant layer made of a flame retardant sheath material on the outer surface of the polyester tape to obtain an electrical unit;

[0017] S2, preparing an optical unit, disposing a layer of aramid yarn on the outer surface of the optical fiber, and disposing a flame retardant layer made of a flame retardant sheath material on the outer surface of the aramid yarn to obtain an optical fiber unit;

[0018] S3, preparing an optoelectronic composite cable core, taking the electrical unit as the central cable, twisting the electrical unit and at least one optical fiber unit into strands, and arranging a first glass fiber tape wrap on the outer surface to obtain an optoelectronic composite cable core;

[0019] S4. An inner sheath made of a flame-retardant sheath material is arranged on the outer surface of the optoelectronic composite cable core, an armor layer is woven on the outer surface of the inner sheath, a second glass fiber tape wrap is arranged on the outer surface of the armor layer, and an outer sheath made of a flame-retardant sheath material is arranged on the second glass fiber tape wrap to obtain an optoelectronic composite cable.

[0020] To be more specific, the preparation method of the flame retardant sheath material is as follows: EVA, EPDM, LDPE, HDPE, compatibilizer, antioxidant, inorganic flame retardant, carbonizing agent and silicone masterbatch are added into a stirrer by weight and mixed thoroughly to obtain a mixture, and the mixture is subjected to a mixing process, a plasticizing process and an extrusion granulation process to obtain a flame retardant sheath material.

[0021] More specifically, in steps S3 and S4, the glass fiber tape is wrapped with a 0.16 mm glass fiber tape, and the overlap rate of the glass fiber tape is controlled at 30% to 40% during wrapping.

[0022] More specifically, in step S4, the braiding coverage density of the armor layer is ≥90%.

[0023] The beneficial effects of the present invention are:

[0024] 1. The optoelectronic composite cable designed in the present invention has multiple layers of highly flame-retardant protective layers. The outer surface of the electrical unit, the outer surface of the optical unit, the inner sheath, and the outer sheath are all made of flame-retardant sheath materials. The optoelectronic composite cable has excellent overall flame-retardant properties, is difficult to burn, produces low smoke during combustion, emits no halogen-related harmful gases, drips zero during combustion, has a short charring distance after combustion, and has a stable carbon shell. There will be no problem of the high-temperature carbon shell being easily broken or falling off after combustion and continuing to ignite other items.

[0025] 2. The flame retardant sheath material designed in this application has good flame retardant effect. The carbonizing agent is a mixture of montmorillonite, red phosphorus and melamine cyanurate in a mass ratio of 2:1:1. The carbonizing agent can quickly produce a carbon layer through a chemical reaction after the cable is burned. The carbon layer protects the internal cable and can prevent the cable from burning and expanding, and has an excellent flame retardant effect. Through the halogen-free formula design, the internal multi-layer sheath material makes the optoelectronic composite cable also have UV resistance, hydrolysis resistance and other properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the optoelectronic composite cable in this application.

[0027] In the figure: 1, electrical unit; 2, optical unit; 31, inner sheath; 32, armor layer; 33, outer sheath. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the specific implementation methods of the present invention are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The present invention provides a highly flame-retardant, zero-drip, low-smoke, halogen-free optical-electrical composite cable for ships and offshore platforms. Figure 1 As shown, the optoelectronic composite cable includes, from inside to outside, an electrical unit 1, at least one optical fiber unit 2, an inner sheath 31, an armor layer 32, and an outer sheath 33.

[0030] In some specific embodiments, the preparation method of the electrical unit 1 is as follows: a wire drawing machine is used to stretch the conductor wire into a conductor monofilament with a diameter of 0.15 mm to 0.20 mm, and then an annealing furnace is used to anneal the conductor monofilament into a conductor monofilament with a breaking elongation of ≥15%, and after treatment, the conductor monofilament is twisted into strands to obtain a cable conductor. An extruder is used to evenly extrude the insulating material on the outer surface of the stranded cable conductor, and then a single twisting machine is used to twist the cable conductor into a cable, and a rock wool rope is filled in the gap, and then a layer of polyester tape is wrapped around the outside, and finally an extruder is used to extrude a layer of zero-drip flame-retardant sheath material on the cable core after the cable is formed, so as to obtain the electrical unit 1.

[0031] In some specific embodiments, the preparation method of the optical unit 2 is specifically as follows: multiple flame-retardant tight-sleeved optical fibers are used as optical transmission media, a layer of aramid yarn is coated on the outside of the optical fiber as a force-reinforced unit to improve the short-term tensile force and flexibility of the optical fiber, and finally a layer of zero-drip flame-retardant sheath material is extruded on the outside of the aramid to obtain the electrical unit 1.

[0032] Among them, factors such as the pay-off tension of the aramid yarn, the pay-off tension of the tight-sleeved optical fiber, and the control of the tightness of the sheath will affect the optical performance of the optical fiber. In this application, the aramid coating is laid evenly, the pay-off tension is controlled between 3 and 5N, and the aramid pitch is controlled between 500-600mm to avoid uneven force on the aramid during the stretching process. At the same time, the pay-off tension of the tight-sleeved optical fiber should also be uniform and consistent, and the pay-off tension is controlled between 1 and 3N, otherwise the strain of the optical fiber will be uneven, which may cause abnormal attenuation and folding of the optical cable. In addition, the structure of the optical unit 2 adopts a fully dry structure, and does not adopt a structure filled with grease. The tight-sleeved optical fiber adopts a tight-sleeved optical fiber made of low-smoke halogen-free LSZH material, and the reinforcing member uses aramid yarn to avoid the use of glass fiber yarn non-metallic wire that produces a lot of smoke after burning, and the sheath of the optical unit 2 uses zero-drip flame-retardant sheath material, thereby ensuring the high flame retardant performance of the optical unit 2.

[0033] During the twisting process of the optical unit 2 and the electrical unit 1, the size and quantity of the optical unit 2 are selected according to actual needs, and the quantity can be 4, 6 or 8. During the twisting process, the electrical unit 1 serves as the central layer support. After twisting, a 0.16mm glass fiber tape is used to wrap the first glass fiber tape layer outside the cable core. The overlap rate of adjacent glass fiber tapes during wrapping is 30%-40%. After wrapping, a layer of zero-drip flame-retardant sheath material is extruded as the inner sheath 31 of the optoelectronic composite cable. After the inner sheath 31 is formed, a galvanized steel wire braided armor layer 32 is used on the inner sheath 31, and the braiding coverage density of the armor layer 32 is ≥90%. After weaving the armor layer 32, a 0.16mm glass fiber tape is used to wrap the second glass fiber tape layer on the armor layer 32. After wrapping, a layer of zero-drip flame-retardant sheath material is extruded as the outer sheath 33 of the optoelectronic composite cable.

[0034] In some specific embodiments, the preparation method of the flame retardant sheath material is specifically as follows: by weight, EVA (ethylene-vinyl acetate copolymer), EPDM (ethylene propylene diene monomer rubber, EPDM4045 is selected), LDPE (low-density polyethylene), HDPE (high-density polyethylene), compatibilizer (maleic anhydride grafted ethylene vinyl acetate), antioxidant (hindered phenol type antioxidant), inorganic flame retardant (aluminum hydroxide and magnesium hydroxide mixture), carbon forming agent (montmorillonite: red phosphorus: melamine cyanurate = 2:1:1) and silicone masterbatch are added to the agitator and mixed evenly to obtain a mixture, and the mixture is subjected to a mixing process, a plasticizing process and an extrusion granulation process to obtain a flame retardant sheath material. Specifically, in the extrusion process, the sheath material mixture passes through four temperature zones with increasing temperatures in the extruder, which are: 90°C in zone 1, 110°C in zone 2, 125°C in zone 3, and 140°C in zone 4. During the use of the flame retardant sheath material, a B1-level special extruder with a screw compression ratio of 1.2 can be used to extrude and melt the zero-drip flame retardant sheath material in five extrusion temperature zones: zone one 135°C, zone two 145°C, zone three 160°C, zone four 165°C, and zone five 165°C. After being shaped by the extrusion die, the material is extruded and wrapped around the cable wrap using an extrusion process.

[0035] The present application also provides a connector for the connection of optoelectronic composite cables. In order to reduce the overall weight of the connector, the outer shell is made of hard aluminum alloy. The interior is a power cord and an optical fiber terminal or an optical fiber connector. After the optoelectronic composite cable is connected and installed, a sealing and pouring glue process is used to inject epoxy resin glue into the connector at room temperature. After condensation, the epoxy glue solidifies all the internal components. The connection accessory achieves IP69 water-blocking performance, and has moisture-proof, waterproof, and salt spray-proof effects. At the same time, it can also prevent optical fiber breakage and attenuation reduction caused by thermal expansion and contraction caused by high and low temperatures and vibration.

[0036] According to the above preparation method, Examples 1 to 4 and Comparative Example 1 were prepared. The weight percentages of the components in the formulas of the Examples and Comparative Examples are shown in the following table:

[0037]

[0038] The performance test results of Examples 1 to 4 and Comparative Example 1 are as follows:

[0039]

[0040] Among them, the carbonization distance refers to the remaining carbonized length of the test piece after the fire supply is stopped in the cable bundle combustion test (Type A). The shorter the carbonization distance, the better the flame retardant effect of the cable. The burning dripping / particle level is determined according to the combustion performance classification test of cables or optical cables specified in GB / T31248. The d0 level is the best level with the least burning dripping.

[0041] According to the above performance test results, Example 3 has the largest tensile strength, the highest elongation at break and the highest oxygen index, the smallest carbonization distance measured after the combustion test, and the burning droplets / particles level reaches d0 level. The flame retardant comprehensive performance of the optoelectronic composite cable prepared according to the specific formula components of Example 3 is the best. The sheath mechanical properties and combustion performance of Example 3 were further measured, and the results are as follows:

[0042]

[0043] The highly flame-retardant, zero-drip, low-smoke, halogen-free optical fiber composite cable designed in this application has excellent performance for ships and offshore platforms. A multi-layer flame-retardant sheath is arranged inside the cable. The sheath has good mechanical properties, high original tensile strength, and high elongation at break. The optical fiber composite cable containing a multi-layer flame-retardant sheath has less smoke after combustion, high smoke transmittance, low smoke toxicity, and weak smoke irritation. In the combustion test, the vertical spread distance of the flame is short, and the cable has less burning drips. The optical fiber composite cable has good flame retardant performance and is suitable for use in ships and offshore platforms.

[0044] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.

Claims

1. A highly flame-retardant, zero-drip, low-smoke, halogen-free optical fiber composite cable for ships and offshore platforms, characterized in that: The invention comprises, from the inside to the outside, an electrical unit, at least one optical fiber unit, an inner sheath, an armor layer, and an outer sheath. The outer surface of the electrical unit, the outer surface of the optical fiber unit, the inner sheath, and the outer sheath are all made of a flame retardant sheath material. The flame retardant sheath material comprises the following components by mass percentage: The carbon-forming agent is composed of montmorillonite, red phosphorus and melamine cyanurate mixed in a mass ratio of 2:1:1, and the inorganic flame retardant includes magnesium hydroxide and aluminum hydroxide, wherein the magnesium hydroxide accounts for 10% to 40% of the total formula content, and the aluminum hydroxide accounts for 10% to 40% of the total formula content.

2. The optoelectronic composite cable according to claim 1, characterized in that: The content of the carbon-forming agent is 2% to 4.5%.

3. The optoelectronic composite cable according to claim 1, characterized in that: The magnesium hydroxide accounts for 15% to 25% of the total formula content, and the aluminum hydroxide accounts for 15% to 25% of the total formula content.

4. The optoelectronic composite cable according to claim 1, characterized in that: The compatibilizer is maleic anhydride grafted ethylene vinyl acetate.

5. The optoelectronic composite cable according to claim 1, characterized in that: The antioxidant is a hindered phenol antioxidant.

6. The optoelectronic composite cable according to claim 1, characterized in that: The armor layer is made of braided galvanized steel wires.

7. A method for preparing the optoelectronic composite cable according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Prepare an electrical unit by twisting at least two cables, filling a rock wool rope in the twisted gap, wrapping a polyester tape around the outer surface after twisting, and arranging a flame retardant layer made of a flame retardant sheath material on the outer surface of the polyester tape to obtain an electrical unit; S2, preparing an optical unit, disposing a layer of aramid yarn on the outer surface of the optical fiber, and disposing a flame retardant layer made of a flame retardant sheath material on the outer surface of the aramid yarn to obtain an optical fiber unit; S3, preparing an optoelectronic composite cable core, taking the electrical unit as the central cable, twisting the electrical unit and at least one optical fiber unit into strands, and arranging a first glass fiber tape wrap on the outer surface to obtain an optoelectronic composite cable core; S4. An inner sheath made of a flame-retardant sheath material is arranged on the outer surface of the optoelectronic composite cable core, an armor layer is woven on the outer surface of the inner sheath, a second glass fiber tape wrap is arranged on the outer surface of the armor layer, and an outer sheath made of a flame-retardant sheath material is arranged on the second glass fiber tape wrap to obtain an optoelectronic composite cable.

8. The preparation method according to claim 7, characterized in that: The preparation method of the flame retardant sheath material is specifically as follows: EVA, EPDM, LDPE, HDPE, compatibilizer, antioxidant, inorganic flame retardant, carbonizing agent and silicone masterbatch are added into a stirrer by weight and mixed thoroughly to obtain a mixture, and the mixture is subjected to a mixing process, a plasticizing process and an extrusion granulation process to obtain the flame retardant sheath material.

9. The preparation method according to claim 7, characterized in that: In step S3, the glass fiber tape wrapping is composed of 0.16 mm glass fiber tape, and the overlap rate of the glass fiber tape is 30% to 40%.

10. The preparation method according to claim 7, characterized in that: In step S4, the braiding coverage density of the armor layer is ≥90%.

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