High-temperature-resistant fireproof flexible cable and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant fireproof flexible cable and a preparation method thereof, and belongs to the technical field of fireproof cables, the high-temperature-resistant fireproof flexible cable comprises a first outer sheath, the inner wall of the first outer sheath is provided with a second outer sheath, and the inner wall of the second outer sheath is provided with an armor. The first outer sheath, the third outer sheath, the fourth outer sheath and the fifth outer sheath are designed and are all made of magnesium-containing flame retardant materials, in a magnesium-containing flame retardant performance test, flame spread is low, the released total heat value is low, the tensile strength is high, the smoke density is low, and at the high temperature, magnesium in the magnesium-containing flame retardant can release water due to the chemical characteristic, so that the flame retardant performance is improved. The cable is good for reducing the combustion temperature and inhibiting flame propagation, and has relatively strong fire resistance and high temperature resistance, and when the first outer sheath is combusted, the magnesium-containing flame retardant is generally halogen-free, generates less harmful gas, and is more environment-friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of fireproof cables, and in particular relates to a high temperature resistant fireproof flexible cable and a preparation method thereof. Background Art

[0002] A cable is an electrical transmission line consisting of one or more conductors and their insulation materials. Its main function is to transmit power, signals or data. It is widely used in power systems, communication networks and various industrial equipment. High-temperature resistant and fire-resistant cables are the most common type. They are cables that can remain functional and safe in the event of a fire. They are mainly used in important power and communication systems to ensure that power or signals can continue to be transmitted in the event of a fire.

[0003] The existing high temperature resistant and fireproof cable structure design is relatively simple, usually using simple fireproof materials for protection, and only protecting the outer layer of the cable, with poor protection performance. In the event of a fire, the protective sheath outside the cable cannot withstand the high temperature combustion, causing the cable to be damaged and deformed, and unable to operate normally and stably. At the same time, the existing fireproof materials will produce harmful gases when burning, affecting the health of people around. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the disadvantages of the above-mentioned prior art and provide a high temperature resistant and fireproof flexible cable and a preparation method thereof.

[0005] The technical solution adopted to solve the above technical problems is: a high temperature resistant and fireproof flexible cable, comprising a first outer sheath, the inner wall of the first outer sheath is provided with a second outer sheath, the inner wall of the second outer sheath is provided with armor, the first outer sheath is made of a magnesium-containing flame retardant material, the magnesium-containing flame retardant performance test has low flame spread, low total calorific value release, high tensile strength and low smoke density, and at high temperatures, the chemical properties of magnesium in the magnesium-containing flame retardant will release moisture, which helps to reduce the combustion temperature and inhibit the spread of flames, and has strong fire resistance and high temperature resistance. When the first outer sheath is burning, the magnesium-containing flame retardant is usually halogen-free, produces less harmful gases, and is more environmentally friendly. In the event of a fire, the cable can operate stably and maintain normal operation of the cable. The second outer sheath is made of aramid fiber, which can maintain stability in a high temperature environment and has good heat resistance, greatly improving the fire prevention and flame retardant effect of the cable, and further protecting the main conductor assembly. When the cable is transported and laid, the armor provides it with physical protection to prevent deformation due to external pressure;

[0006] The inner wall of the armor is provided with an inner sheath, the inner wall of the inner sheath is provided with a wrapping layer, the inner wall of the wrapping layer is provided with a first filling layer, the inner sheath provides protection for the wrapping layer, the wrapping layer can protect the internal material from the influence of the external environment, prevent corrosion and degradation, the first filling layer can increase the overall strength and stability of the material, and provide a supporting effect for the main conductor assembly, multiple secondary conductor assemblies and multiple control assemblies;

[0007] A main conductor assembly is provided in the first filling layer, and a plurality of secondary conductor assemblies are provided around the main conductor assembly in the first filling layer, the secondary conductor assembly includes a secondary core conductor arranged in the first filling layer, the outer wall of the secondary core conductor is covered with a secondary conductor insulating component, the outer wall of the secondary conductor insulating component is covered with a fourth outer sheath, the outer wall of the fourth outer sheath is provided with a pressure-resistant sleeve, the secondary core conductor is a copper core, has excellent electrical conductivity, can effectively transmit current, and reduce energy loss, the secondary conductor insulating component prevents current from leaking from the secondary core conductor to the external environment, ensures that the current flows along the correct path, and provides physical protection for the secondary core conductor at the same time, and when the main core conductor is damaged, signals can be transmitted through multiple secondary core conductors for backup use without affecting normal signal transmission, the fourth outer sheath is made of magnesium-containing flame retardant material, and has strong high temperature resistance and fire resistance. When the first outer sheath is burned out, the secondary core conductor is doubly protected by the fourth outer sheath, so that the secondary core conductor It can operate stably. A plurality of control components are arranged around the main conductor component in the first filling layer. The control components include a second filling layer arranged in the first filling layer. The outer wall of the second filling layer is covered with a fifth outer sheath. A plurality of control conductor insulating parts are arranged in the center of the second filling layer. The inner walls of the plurality of control conductor insulating parts are provided with control conductor shielding. The inner centers of the plurality of control conductor shielding are provided with control core conductors. The control core conductors can quickly locate the damaged points, which helps the staff to repair them quickly. The control conductor shielding is protected from external electromagnetic influences and reduces interference to surrounding equipment. The control conductor shielding can reduce electromagnetic interference and ensure stable signal transmission. The second filling layer provides support for the plurality of control core conductors. The fifth outer sheath is made of magnesium-containing flame retardant material and has strong high temperature resistance and fire resistance. When the first outer sheath is burned, the control core conductors are doubly protected by the fifth outer sheath, so that the control core conductors can operate stably.

[0008] Furthermore, the main conductor assembly includes a main core conductor arranged in the first filling layer, the outer wall of the main core conductor is covered with a main conductor insulation component, and the outer wall of the main conductor insulation component is covered with a third outer sheath.

[0009] Through the above technical solution, the main core conductor is a copper core with excellent electrical conductivity, which can effectively transmit current and reduce energy loss. The main conductor insulation component prevents current from leaking from the main core conductor to the external environment, ensuring that the current flows along the correct path while providing physical protection for the main core conductor. The third outer sheath is made of magnesium-containing flame retardant material, which is resistant to high temperature and has strong fire resistance. When the first outer sheath is burned, the main core conductor is doubly protected by the third outer sheath, so that the main core conductor can operate stably.

[0010] Furthermore, the outer wall of the fourth outer protective sleeve is fixedly connected with a plurality of supporting arch strips, the inner wall of the pressure-resistant sleeve is provided with a plurality of buffer arch sleeves, and the plurality of buffer arch sleeves cover the corresponding supporting arch strips.

[0011] Through the above technical solution, when the pressure-resistant sleeve is subjected to external pressure, the pressure-resistant sleeve transfers the pressure to multiple buffer arch sleeves, so that the multiple buffer arch sleeves buffer the applied pressure. At the same time, the multiple buffer arch sleeves transfer the pressure to the corresponding supporting arch strips, so that the multiple supporting arch strips disperse the pressure and improve their bearing capacity, thereby reducing the extrusion of the fourth outer sheath and preventing the secondary conductor assembly from being deformed due to excessive pressure.

[0012] A method for preparing a high temperature resistant and fireproof flexible cable comprises the following specific steps:

[0013] Step 1: spray the main conductor insulation component on the outer wall of the main core conductor through the electro-coating equipment, and then cover the third outer sheath on the outer wall of the main conductor insulation component through the twin-screw extruder to complete the processing of the main core conductor;

[0014] Step 2: spray the secondary conductor insulation component on the outer wall of the secondary core conductor through the electrocoating equipment, then cover the fourth outer sheath on the outer wall of the secondary conductor insulation component through the twin-screw extruder, and then cover the compression sleeve on the outer side of the fourth outer sheath to complete the processing of the secondary core conductor;

[0015] Step 3: Use a hot air gun to heat and bond the cut control conductor shield to the outer wall of the control wire core conductor, spray the control conductor insulation component on the outer wall of the control conductor shield through the electro-coating equipment, and then use a twin-screw extruder to cover the fifth outer sheath on the outside of multiple control conductor insulation components, and use a filling machine to fill the second filling layer inside to ensure sealing;

[0016] Step 4: Use a wrapping machine to wrap the wrapping layer on the outside of the main conductor assembly, multiple secondary conductor assemblies and multiple control assemblies, and use a filling machine to fill the inside with the first filling layer to ensure sealing. Use a twin-screw extruder to extrude and wrap the inner sheath on the outside of the wrapping layer. Use an armoring machine to wrap the armor on the outside of the inner sheath to ensure that the joints and ports of the armor are well sealed to prevent moisture and impurities from entering. Use a twin-screw extruder to extrude and wrap the second outer sheath on the outside of the armor. Finally, use a twin-screw extruder to extrude and wrap the first outer sheath on the outside of the second outer sheath to complete the preparation of the cable.

[0017] The materials of the first outer sheath, the third outer sheath, the fourth outer sheath and the fifth outer sheath are all magnesium-containing flame retardants, which include the following raw materials in parts by weight: 60-70 parts of polyethylene, 35-45 parts of magnesium hydroxide, 6-10 parts of hydrotalcite, and 0.06-3 parts of phthalate coupling agent.

[0018] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0019] S1, put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add calcium carbonate, heat and stir;

[0020] S2, adding titanate coupling agent into the reaction kettle and continuing stirring;

[0021] S3, filtering the mixture in the reactor, drying it, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0022] Furthermore, the mass of calcium carbonate added to S1 is 3-5 parts, and the temperature of heating and stirring is 60-80°C.

[0023] Furthermore, the stirring time in S2 is 10 to 15 minutes.

[0024] Furthermore, in S3, the drying temperature is 100-120° C., and the drying time is 40-50 min.

[0025] The beneficial effects of the present invention are as follows: (1) The present invention is designed with a first outer sheath, a third outer sheath, a fourth outer sheath and a fifth outer sheath, and all of them are made of magnesium-containing flame retardant materials. In the performance test of the magnesium-containing flame retardant, the flame spread is low, the total calorific value is low, the tensile strength is high and the smoke density is low. At high temperatures, the chemical properties of magnesium in the magnesium-containing flame retardant will release moisture, which helps to reduce the combustion temperature and inhibit the spread of flames. It has strong fire resistance and high temperature resistance. When the first outer sheath is burning, the magnesium-containing flame retardant is usually halogen-free, produces less harmful gases, and is more environmentally friendly. (2) The present invention is designed with a main conductor component, a secondary conductor component and a control conductor insulation component, and their protective covers are all made of magnesium-containing flame retardant materials to provide double protection. In the event of a fire, the cable can operate stably and maintain normal operation of the cable. When the main core conductor is damaged, the signal can be transmitted through multiple secondary core conductors for backup use without affecting normal signal transmission. Multiple control core conductors can quickly locate the damaged point, which helps the staff to quickly repair it, greatly improving the service life of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is an appearance diagram of the present invention;

[0027] Figure 2 It is a front view of the present invention;

[0028] Figure 3 is a cross-sectional view of a main conductor assembly of the present invention;

[0029] Figure 4 is a schematic structural diagram of a secondary conductor assembly of the present invention;

[0030] Figure 5 It is a schematic diagram of the control component structure of the present invention;

[0031] Figure 6 for Figure 1 A partial enlarged view of the middle A;

[0032] Figure 7 for Figure 4 A partial enlarged view of point B in the middle.

[0033] Figure markings: 1. first outer sheath; 2. second outer sheath; 3. armor; 4. inner sheath; 5. winding layer; 6. first filling layer; 7. main conductor assembly; 701. main core conductor; 702. main conductor insulation component; 703. third outer sheath; 8. secondary conductor assembly; 801. secondary core conductor; 802. secondary conductor insulation component; 803. fourth outer sheath; 8031. supporting arch strip; 804. pressure-resistant sleeve; 8041. buffer arch sleeve; 9. control assembly; 901. second filling layer; 902. fifth outer sheath; 903. control conductor insulation component; 904. control conductor shielding; 905. control core conductor. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] like Figure 1-Figure 7 As shown, a high temperature resistant and fireproof flexible cable of the present embodiment comprises a first outer sheath 1, the inner wall of the first outer sheath 1 is provided with a second outer sheath 2, the inner wall of the second outer sheath 2 is provided with an armor 3, the first outer sheath 1 is made of a magnesium-containing flame retardant material, the magnesium-containing flame retardant performance test has low flame spread, low total calorific value release, high tensile strength and low smoke density, and at high temperatures, the chemical properties of magnesium in the magnesium-containing flame retardant will release moisture, which helps to reduce the combustion temperature and inhibit the spread of flames, and has strong fire resistance and high temperature resistance. When the first outer sheath 1 is burning, the magnesium-containing flame retardant is usually halogen-free, produces less harmful gases, is more environmentally friendly, and enables the cable to operate stably in the event of a fire, maintaining the normal operation of the cable, and the first outer sheath 1 is made of a magnesium-containing flame retardant material. The second outer sheath 2 is made of aramid fiber, which can maintain stability in high temperature environment and has good heat resistance, greatly improving the fire prevention and flame retardant effect of the cable, and further protecting the main conductor component 7. When the cable is transported and laid, the armor 3 provides it with physical protection to prevent deformation due to external pressure. The inner wall of the armor 3 is provided with an inner sheath 4, and the inner wall of the inner sheath 4 is provided with a wrapping layer 5. The inner wall of the wrapping layer 5 is provided with a first filling layer 6. The inner sheath 4 provides protection for the wrapping layer 5. The wrapping layer 5 can protect the internal material from the influence of the external environment and prevent corrosion and degradation. The first filling layer 6 can increase the overall strength and stability of the material, and provide support for the main conductor component 7, multiple secondary conductor components 8 and multiple control components 9.

[0036] like Figure 1-Figure 3 As shown, a main conductor assembly 7 is provided in the first filling layer 6, and the main conductor assembly 7 includes a main core conductor 701 arranged in the first filling layer 6, and the outer wall of the main core conductor 701 is covered with a main conductor insulating component 702, and the outer wall of the main conductor insulating component 702 is covered with a third outer sheath 703. The main core conductor 701 is a copper core, has excellent electrical conductivity, can effectively transmit current, and reduce energy loss. The main conductor insulating component 702 prevents current from leaking from the main core conductor 701 to the external environment, ensures that the current flows along the correct path, and provides physical protection for the main core conductor 701. The third outer sheath 703 is made of magnesium-containing flame retardant material, is resistant to high temperature and has strong fire resistance. When the first outer sheath 1 is burned, the main core conductor 701 is doubly protected by the third outer sheath 703, so that the main core conductor 701 can operate stably.

[0037] like Figure 1-Figure 4As shown, a plurality of secondary conductor assemblies 8 are arranged around the main conductor assembly 7 in the first filling layer 6, and the secondary conductor assembly 8 includes a secondary core conductor 801 arranged in the first filling layer 6, and the outer wall of the secondary core conductor 801 is covered with a secondary conductor insulating component 802, and the outer wall of the secondary conductor insulating component 802 is covered with a fourth outer sheath 803. The secondary core conductor 801 is a copper core, has excellent electrical conductivity, can effectively transmit current, and reduce energy loss. The secondary conductor insulating component 802 prevents current from leaking from the secondary core conductor 801 to the external environment, ensures that the current flows along the correct path, and provides physical protection for the secondary core conductor 801. When the main core conductor 701 is damaged, signals can be transmitted through multiple secondary core conductors 801 for backup use without affecting normal signal transmission. The fourth outer sheath 803 is made of a magnesium-containing flame retardant material, which is resistant to high temperature and The fire resistance is strong. When the first outer sheath 1 is burned, the secondary core conductor 801 is doubly protected by the fourth outer sheath 803, so that the secondary core conductor 801 can operate stably. The outer wall of the fourth outer sheath 803 is fixedly connected with multiple supporting arch strips 8031. The inner wall of the pressure-resistant sleeve 804 is provided with multiple buffer arch sleeves 8041. The multiple buffer arch sleeves 8041 cover the corresponding supporting arch strips 8031. When the pressure-resistant sleeve 804 is subjected to external pressure, the pressure-resistant sleeve 804 transfers the pressure to the multiple buffer arch sleeves 8041, so that the multiple buffer arch sleeves 8041 buffer the applied pressure. At the same time, the multiple buffer arch sleeves 8041 transfer the pressure to the corresponding supporting arch strips 8031, so that the multiple supporting arch strips 8031 ​​disperse the pressure and improve its bearing capacity, thereby reducing the extrusion of the fourth outer sheath 803 and preventing the secondary conductor assembly 8 from being deformed due to excessive pressure.

[0038] like Figure 1-Figure 5 As shown, a plurality of control components 9 are arranged around the main conductor component 7 in the first filling layer 6, and the control component 9 includes a second filling layer 901 arranged in the first filling layer 6, the outer wall of the second filling layer 901 is covered with a fifth outer sheath 902, a plurality of control conductor insulating components 903 are arranged in the center of the second filling layer 901, the inner walls of the plurality of control conductor insulating components 903 are all provided with control conductor shields 904, and the inner centers of the plurality of control conductor shields 904 are all provided with control wire core conductors 905, and the control wire core conductors 905 can quickly locate the damaged point, which helps the staff to repair it quickly, protects the control conductor shielding 904 from external electromagnetic influences, reduces interference to surrounding equipment, and reduces electromagnetic interference to ensure stable signal transmission. The second filling layer 901 provides a supporting effect for multiple control core conductors 905. The fifth outer sheath 902 is made of magnesium-containing flame retardant material, which is resistant to high temperature and has strong fire resistance. When the first outer sheath 1 is burned, the control core conductor 905 is doubly protected by the fifth outer sheath 902, so that the control core conductor 905 can operate stably.

[0039] A method for preparing a high temperature resistant and fireproof flexible cable comprises the following specific steps:

[0040] Step 1: spray the main conductor insulation component 702 on the outer wall of the main core conductor 701 by electro-coating equipment, and then cover the third outer sheath 703 on the outer wall of the main conductor insulation component 702 by a twin-screw extruder to complete the processing of the main core conductor 701;

[0041] Step 2: spray the secondary conductor insulating component 802 on the outer wall of the secondary core conductor 801 by an electrocoating device, and then cover the fourth outer sheath 803 on the outer wall of the secondary conductor insulating component 802 by a twin-screw extruder, and then cover the compression sleeve 804 on the outer side of the fourth outer sheath 803 to complete the processing of the secondary core conductor 801;

[0042] Step 3: Use a hot air gun to heat and bond the cut control conductor shield 904 to the outer wall of the control core conductor 905, spray the control conductor insulation component 903 on the outer wall of the control conductor shield 904 through an electro-coating device, and then use a twin-screw extruder to cover the fifth outer sheath 902 on the outer side of the plurality of control conductor insulation components 903, and use a filling machine to fill the second filling layer 901 inside to ensure sealing;

[0043] Step 4: Use a wrapping machine to wrap the wrapping layer 5 on the outside of the main conductor component 7, multiple secondary conductor components 8 and multiple control components 9, and fill the inside with the first filling layer 6 through a filling machine to ensure sealing, extrude the inner sheath 4 and wrap it on the outside of the wrapping layer 5 through a twin-screw extruder, and wrap the armor 3 on the outside of the inner sheath 4 through an armoring machine to ensure that the joints and ports of the armor 3 are well sealed to prevent moisture and impurities from entering, and then extrude the second outer sheath 2 and wrap it on the outside of the armor 3 through a twin-screw extruder, and finally extrude the first outer sheath 1 and wrap it on the outside of the second outer sheath 2 through a twin-screw extruder to complete the preparation of the cable.

[0044] Preparation of magnesium flame retardant materials:

[0045] Embodiment 1:

[0046] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 60 parts of polyethylene, 35 parts of magnesium hydroxide, 6 parts of hydrotalcite, 0.06 parts of phthalate coupling agent and 3 parts of calcium carbonate.

[0047] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0048] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 3 parts of calcium carbonate, heat to 60°C and stir;

[0049] S2, add 0.06 parts of titanate coupling agent into the reactor and continue stirring for 10 minutes;

[0050] S3, filtering the mixture in the reactor, drying it at 100°C for 40 minutes, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0051] Embodiment 2:

[0052] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 65 parts of polyethylene, 40 parts of magnesium hydroxide, 8 parts of hydrotalcite, 0.15 parts of phthalate coupling agent and 4 parts of calcium carbonate.

[0053] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0054] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 4 parts of calcium carbonate, heat to 60°C and stir;

[0055] S2, add 0.15 parts of titanate coupling agent into the reactor and continue stirring for 10 minutes;

[0056] S3, filtering the mixture in the reactor, drying it at 100°C for 40 minutes, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0057] Embodiment three:

[0058] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 70 parts of polyethylene, 45 parts of magnesium hydroxide, 10 parts of hydrotalcite, 3 parts of phthalate coupling agent and 6 parts of calcium carbonate.

[0059] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0060] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 6 parts of calcium carbonate, heat to 60°C and stir;

[0061] S2. Add 3 parts of titanate coupling agent into the reactor and continue stirring for 10 minutes;

[0062] S3, filtering the mixture in the reactor, drying it at 100°C for 40 minutes, and sieving it after drying to obtain a finished magnesium-containing flame retardant

[0063] Embodiment 4:

[0064] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 60 parts of polyethylene, 35 parts of magnesium hydroxide, 6 parts of hydrotalcite, 0.06 parts of phthalate coupling agent and 3 parts of calcium carbonate.

[0065] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0066] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 3 parts of calcium carbonate, heat to 70°C and stir;

[0067] S2, add 0.06 parts of titanate coupling agent into the reactor and continue stirring for 12 minutes;

[0068] S3, filtering the mixture in the reactor, drying it at 110° C. for 45 min, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0069] Embodiment five:

[0070] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 60 parts of polyethylene, 35 parts of magnesium hydroxide, 6 parts of hydrotalcite, 0.06 parts of phthalate coupling agent and 3 parts of calcium carbonate.

[0071] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0072] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 3 parts of calcium carbonate, heat to 80°C and stir;

[0073] S2, add 0.06 parts of titanate coupling agent into the reactor and continue stirring for 15 minutes;

[0074] S3, filtering the mixture in the reactor, drying it at 120° C. for 50 min, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0075] Embodiment six:

[0076] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 65 parts of polyethylene, 40 parts of magnesium hydroxide, 8 parts of hydrotalcite, 0.15 parts of phthalate coupling agent and 4 parts of calcium carbonate.

[0077] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0078] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 4 parts of calcium carbonate, heat to 70°C and stir;

[0079] S2, add 0.15 parts of titanate coupling agent into the reactor and continue stirring for 12 minutes;

[0080] S3, filtering the mixture in the reactor, drying it at 110° C. for 45 min, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0081] Embodiment seven:

[0082] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 65 parts of polyethylene, 40 parts of magnesium hydroxide, 8 parts of hydrotalcite, 0.15 parts of phthalate coupling agent and 4 parts of calcium carbonate.

[0083] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0084] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 4 parts of calcium carbonate, heat to 80°C and stir;

[0085] S2, add 0.15 parts of titanate coupling agent into the reactor and continue stirring for 15 minutes;

[0086] S3, filtering the mixture in the reactor, drying it at 120° C. for 50 min, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0087] Embodiment eight:

[0088] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 70 parts of polyethylene, 45 parts of magnesium hydroxide, 10 parts of hydrotalcite, 3 parts of phthalate coupling agent and 6 parts of calcium carbonate.

[0089] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0090] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 6 parts of calcium carbonate, heat to 70°C and stir;

[0091] S2. Add 3 parts of titanate coupling agent into the reactor and continue stirring for 12 minutes;

[0092] S3, filtering the mixture in the reactor, drying it at 110° C. for 45 min, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0093] Embodiment nine:

[0094] The magnesium-containing flame retardant comprises the following raw materials in parts by weight: 70 parts of polyethylene, 45 parts of magnesium hydroxide, 10 parts of hydrotalcite, 3 parts of phthalate coupling agent and 6 parts of calcium carbonate.

[0095] The preparation method of the magnesium-containing flame retardant comprises the following specific steps:

[0096] S1. Put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add 6 parts of calcium carbonate, heat to 80°C and stir;

[0097] S2. Add 3 parts of titanate coupling agent into the reactor and continue stirring for 15 minutes;

[0098] S3, filtering the mixture in the reactor, drying it at 120° C. for 50 min, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

[0099] Comparative Example 1:

[0100] The difference between Comparative Example 1 and Example 1 is that the magnesium hydroxide in the raw material used is aluminum hydroxide.

[0101] Comparative Example 2:

[0102] The difference between Comparative Example 2 and Example 1 is that no hydrotalcite is used in the raw materials.

[0103] Comparative Example 3:

[0104] The difference between Comparative Example 3 and Example 1 is that no calcium carbonate is added to the raw materials during mixing and stirring.

[0105] Comparative Example 4:

[0106] The difference between Comparative Example 4 and Example 1 is that no titanate coupling agent is added to the raw materials during mixing and stirring.

[0107] The performance tests were performed on the cables prepared in Examples 1-9 and Comparative Examples 1-4. The test methods are shown in Table 1.

[0108] Refer to the national standard GB 31247-2014 "Classification of Combustion Performance of Electrical Cables and Optical Cables" indicator requirements:

[0109] Total calorific value released: the total heat released when a unit mass of material is completely burned and all the water vapor in the combustion products condenses into water.

[0110] Flame spread: The maximum carbonization distance produced by the flame on the surface of bundled cables measured according to GB / T 31248.

[0111] Tensile strength: The maximum stress that a cable can withstand when subjected to tensile force in the test according to GB / T 31248-2014.

[0112] Smoke density (minimum light transmittance): minimum light transmittance measured according to GB / T 17651.2.

[0113] Table 1

[0114] Flame spread (m) Total calorific value released (MJ) Tensile strength (Mpa) Smoke density (%) Embodiment 1 1.8 3.5 18.5 30% Embodiment 2 2.2 4.8 17.5 35% Embodiment 3 2.7 5.7 15.6 42% Embodiment 4 1.98 3.3 18.3 32% Embodiment 5 2.05 3.2 18.2 33% Embodiment 6 2.3 4.9 17.3 37% Embodiment 7 2.5 5.2 16.8 39% Embodiment 8 2.8 5.9 15.3 44% Embodiment 9 3.0 6.2 14.8 47% Comparative Example 1 5.5 12.5 11.5 56% Comparative Example 2 3.8 8.5 13.8 50% Comparative Example 3 4.2 9.8 14.5 52% Comparative Example 4 4.8 10.3 12.8 54%

[0115] As can be seen from Table 1, the present invention compares Example 1 with Example 2 and Example 3, adds different amounts of polyethylene, magnesium hydroxide, hydrotalcite, titanate coupling agent and calcium carbonate, and the final test performance data are different, and Example 1 has the best comprehensive performance; the present invention compares Example 1 with Example 4 and Example 5, and Example 2 with Example 6 and Example 7, and Example 3 with Example 8 and Example 9, and the different stirring temperatures, stirring times, drying temperatures and drying times affect the final test performance data, and Example 1 has the best comprehensive performance; the present invention compares Example 1 with Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, and the test performance of using magnesium hydroxide in the raw material is better than that of using aluminum hydroxide, and the test performance of using hydrotalcite, phthalate coupling agent and calcium carbonate in the raw material is better than that of not using hydrotalcite, phthalate coupling agent and calcium carbonate.

[0116] In summary, in the performance test of magnesium-containing flame retardants, the flame spread is low, the total calorific value released is low, the tensile strength is high and the smoke density is low. At high temperatures, the chemical properties of magnesium in magnesium-containing flame retardants will release moisture, which helps to reduce the combustion temperature and inhibit the spread of flames. It has strong fire resistance and high temperature resistance. In addition, magnesium-containing flame retardants are usually halogen-free, produce less harmful gases, and are more environmentally friendly. In the event of a fire, magnesium-containing flame retardants can be flame-retardant and heat-insulating, allowing the cable to operate stably.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention.

Claims

1. A high temperature resistant and fireproof flexible cable, comprising a first outer sheath (1), characterized in that: The inner wall of the first outer sheath (1) is provided with a second outer sheath (2), and the inner wall of the second outer sheath (2) is provided with armor (3); The inner wall of the armor (3) is provided with an inner sheath (4), the inner wall of the inner sheath (4) is provided with a wrapping layer (5), and the inner wall of the wrapping layer (5) is provided with a first filling layer (6); A main conductor assembly (7) is provided in the first filling layer (6), and a plurality of secondary conductor assemblies (8) are provided in the first filling layer (6) near the main conductor assembly (7). The secondary conductor assembly (8) comprises a secondary core conductor (801) provided in the first filling layer (6), the outer wall of the secondary core conductor (801) is covered with a secondary conductor insulating component (802), the outer wall of the secondary conductor insulating component (802) is covered with a fourth outer sheath (803), the outer wall of the fourth outer sheath (803) is provided with a pressure-resistant sleeve (804), and the first filling layer (6) is provided with a plurality of secondary conductor assemblies (88) near the main conductor assembly (7). ) is provided around the main conductor component (7) in the inner part, the control component (9) comprising a second filling layer (901) provided in the first filling layer (6), the outer wall of the second filling layer (901) being covered with a fifth outer sheath (902), a plurality of control conductor insulating components (903) being provided at the center of the second filling layer (901), the inner walls of the plurality of control conductor insulating components (903) being provided with control conductor shields (904), and the inner centers of the plurality of control conductor shields (904) being provided with control wire core conductors (905).

2. A high temperature resistant and fireproof flexible cable according to claim 1, characterized in that: The main conductor assembly (7) comprises a main core conductor (701) arranged in a first filling layer (6), the outer wall of the main core conductor (701) being covered with a main conductor insulating component (702), and the outer wall of the main conductor insulating component (702) being covered with a third outer sheath (703).

3. A high temperature resistant and fireproof flexible cable according to claim 2, characterized in that: The outer wall of the fourth outer protective sleeve (803) is fixedly connected to a plurality of supporting arch strips (8031), and the inner wall of the pressure-resistant sleeve (804) is provided with a plurality of buffer arch sleeves (8041), and the plurality of buffer arch sleeves (8041) cover corresponding supporting arch strips (8031).

4. A method for preparing a high temperature resistant and fireproof flexible cable according to any one of claims 1 to 3, characterized in that: The specific steps include: The first step is to spray the main conductor insulation component (702) on the outer wall of the main line core conductor (701) by means of an electrocoating device, and then to cover the third outer sheath (703) on the outer wall of the main conductor insulation component (702) by means of a twin-screw extruder, thereby completing the processing of the main line core conductor (701); Step 2: spray the secondary conductor insulation component (802) onto the outer wall of the secondary core conductor (801) by means of an electrocoating device, and then wrap the fourth outer sheath (803) onto the outer wall of the secondary conductor insulation component (802) by means of a twin-screw extruder, and then wrap the compression sleeve (804) onto the outer side of the fourth outer sheath (803), thereby completing the processing of the secondary core conductor (801); Step 3: Use a hot air gun to heat and bond the cut control conductor shield (904) to the outer wall of the control core conductor (905), spray the control conductor insulation component (903) on the outer wall of the control conductor shield (904) through an electro-coating device, and then use a twin-screw extruder to cover the fifth outer sheath (902) on the outer side of the plurality of control conductor insulation components (903), and use a filling machine to fill the second filling layer (901) inside to ensure sealing; Step 4: The wrapping layer (5) is wrapped around the outer sides of the main conductor assembly (7), the plurality of secondary conductor assemblies (8) and the plurality of control assemblies (9) by a wrapping machine, and the first filling layer (6) is filled inside the inner sides by a filling machine to ensure the sealing property, the inner sheath (4) is extruded and wrapped around the outer sides of the wrapping layer (5) by a twin-screw extruder, the armor (3) is wrapped around the outer sides of the inner sheath (4) by an armoring machine, and the connection and port of the armor (3) are ensured to be well sealed to prevent moisture and impurities from entering, the second outer sheath (2) is extruded and wrapped around the outer sides of the armor (3) by a twin-screw extruder, and finally the first outer sheath (1) is extruded and wrapped around the outer sides of the second outer sheath (2) by a twin-screw extruder to complete the preparation of the cable.

5. The method for preparing a high temperature resistant and fireproof flexible cable according to claim 4, characterized in that: The materials of the first outer sheath (1), the third outer sheath (703), the fourth outer sheath (803) and the fifth outer sheath (902) are all magnesium-containing flame retardants, and the magnesium-containing flame retardants include the following raw materials in parts by weight: 60-70 parts of polyethylene, 35-45 parts of magnesium hydroxide, 6-10 parts of hydrotalcite, and 0.06-3 parts of phthalate coupling agent.

6. The method for preparing a high temperature resistant and fireproof flexible cable according to claim 5, characterized in that: The preparation method of the magnesium-containing flame retardant comprises the following specific steps: S1, put polyethylene, magnesium hydroxide and hydrotalcite into a reaction kettle and mix them evenly, then slowly add calcium carbonate, heat and stir; S2, adding titanate coupling agent into the reaction kettle and continuing stirring; S3, filtering the mixture in the reactor, drying it, and sieving it after drying to obtain a finished magnesium-containing flame retardant.

7. The method for preparing a high temperature resistant and fireproof flexible cable according to claim 6, characterized in that: The mass of calcium carbonate added to S1 is 3-5 parts, and the temperature for heating and stirring is 60-80°C.

8. The method for preparing a high temperature resistant and fireproof flexible cable according to claim 6, characterized in that: The stirring time in S2 is 10 to 15 minutes.

9. The method for preparing a high temperature resistant and fireproof flexible cable according to claim 6, characterized in that: In S3, the drying temperature is 100-120° C., and the drying time is 40-50 min.

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