A B1 grade flame-retardant double-twisted cloth wire irradiation cross-linking low-smoke halogen-free low-toxicity insulating material and its preparation method

Abstract

The application relates to the technical field of insulating materials, and particularly discloses a B1-grade flame-retardant radiation crosslinking low-smoke halogen-free low-toxicity insulating material for twisted-pair cloth electric wires and a preparation method thereof. The insulating material has low combustion grade, combustion dripping grade and combustion heat release, and has good processing performance, self-extinguishing performance and insulating performance. Compared with B1-grade cable materials on the market, the insulating material is more suitable for use in power facilities.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of insulating materials, and more particularly to an irradiation cross-linked low-smoke halogen-free low-toxicity insulating material for B1-grade flame-retardant twisted cloth wire and a preparation method thereof. BACKGROUND

[0002] With the development of society, fire safety problems are increasingly valued. When a fire occurs, the wire and cable can become a way for the fire to spread, and the flammable insulation or sheath material can cause the fire accident to expand, burn out the power supply and lines of fire-fighting equipment, affect the normal operation of fire-fighting electrical equipment, delay the fire-fighting time, and easily cause loss of life and property. In addition, the heat, toxic gases and smoke emitted during the burning of the wire and cable insulation and sheath material can further harm life and property.

[0003] Previously commonly used flame-retardant cables in China are manufactured in accordance with the technical standard of GB / T 19666-2005 General Requirements for Flame Retardant and Fire Resistant Cables. The standard for evaluating the flame-retardant grade of wire and cable is GB / T 18380-2008, which evaluates the burning grade of wire and cable through the carbonization height after burning. In order to make fire safety more scientific and reasonable, and to minimize the potential fire hazards, the compulsory national standard GB 31247-2014 Classification of Burning Behavior of Cables and Optical Fibers was issued on December 5, 2014. The standard puts forward higher requirements for the performance of flame-retardant cables by quantifying the technical indexes of the classification of the burning behavior of cables and optical fibers. Under such a background, it is inevitable to develop and use B1-grade flame-retardant cables to improve the flame-retardant performance of wire and cable, reduce the heat release, smoke production, burning drop / microparticle grade, smoke toxicity grade, and corrosive grade, etc. when a fire occurs, and to protect the safety of life and property.

[0004] B1-grade flame-retardant twisted cloth wire has a special structure, which is usually first wrapped with mica tape outside the five types of soft conductor, then wrapped with insulating material outside the mica tape by using the extrusion tube production method, and finally obtained after irradiation cross-linking. Currently, the flame-retardant system of B1-grade cable material on the market generally uses metal hydroxide as a flame retardant, and also uses a nano char-forming agent as a flame-retardant synergist.

[0005] In view of the related technology in the above, the inventors believe that the special structure of B1-grade flame-retardant twisted cloth wire is not conducive to achieving flame retardation, and irradiation cross-linking also affects the insulating performance of the insulating material. Moreover, the flame-retardant system composed of metal hydroxide and nano char-forming agent is actually not suitable for use in B1-grade flame-retardant twisted cloth wire, which leads to the fact that B1-grade flame-retardant twisted cloth wire is difficult to have a lower burning grade, burning drop grade, and burning heat release under the existing process conditions and flame-retardant system, and is also difficult to have good processing performance, self-extinguishing performance, and insulating performance. SUMMARY

[0006] In the related art, it is difficult for the B1-grade flame-retardant braided cloth wire to have lower combustion grade, combustion dripping grade and combustion heat release under the existing process conditions and flame-retardant system, and it is also difficult to have good processing performance, self-extinguishing performance and insulation performance. In order to improve this defect, the present application provides a kind of B1-grade flame-retardant braided cloth wire for irradiation crosslinking low-smoke halogen-free low-toxicity insulation material and its preparation method.

[0007] In the first aspect, the present application provides a kind of B1-grade flame-retardant braided cloth wire for irradiation crosslinking low-smoke halogen-free low-toxicity insulation material, adopts the following technical scheme:

[0008] A kind of B1-grade flame-retardant braided cloth wire for irradiation crosslinking low-smoke halogen-free low-toxicity insulation material, it includes the following weight parts of components: base material composition 80-100 parts, magnesium hydroxide 180-220 parts, antimony trioxide 20-50 parts, melamine cyanurate 9.5-10.5 parts, auxiliary agent 9-10 parts, the auxiliary agent includes silane coupling agent, antioxidant, crosslinking sensitizing agent, lubricant and light stabilizer, the component of the base material composition includes EVA resin and compatibilizer, the d 50 Particle size is 0.5-1 μm.

[0009] By adopting the above technical scheme, the present application designs a new flame-retardant system in combination with the characteristics of B1-grade flame-retardant braided cloth wire, selects d 50 Particle size is 0.5 μm as the only hydroxide flame-retardant component, and the amount of magnesium hydroxide is limited. According to the amount limited by the present application, magnesium hydroxide can fully promote the combustion crust of the insulation material without containing nanometer carbonation agent, and the combustion crust effect is obviously better than that of adding aluminum hydroxide or magnesium-aluminum compound flame-retardant system, and a carbon layer with high integrity can be obtained after combustion. The present application also selects antimony trioxide and melamine cyanurate as flame-retardant synergists, antimony trioxide isolates air and combustible gas through condensed phase flame-retardant mechanism during insulation material combustion, while melamine cyanurate dilutes combustible gas and oxygen through gas phase flame-retardant mechanism, and the self-extinguishing performance of the insulation material can be fully improved by the promotion effect of magnesium hydroxide on combustion crust. On this basis, by limiting the amount of antimony trioxide and melamine cyanurate, the insulation material of the present application can not only meet the self-extinguishing performance standard, but also ensure that the corrosion grade and smoke toxicity index meet the standard, overcoming the defects of high price, large specific gravity and large amount of antimony trioxide and the influence of gas released by melamine cyanurate combustion on material toxicity index. Based on the above reasons, the insulation material of the present application not only has lower combustion grade, combustion dripping grade and combustion heat release, but also has good processing performance, self-extinguishing performance and insulation performance, and is more suitable for use in wire and cable than B1-grade cable material on the market.

[0010] Preferably, the EVA resin is used in an amount of 40-87.5% by weight of the total base composition.

[0011] By using the above technical solution, the application preferably uses the EVA resin in the above range, and the insulation material prepared in the above range has good compatibility with the flame-retardant system of the application, can have lower combustion grade, combustion dripping grade and combustion heat release, and has good self-extinguishing performance.

[0012] Preferably, the compatilizer is EVA grafted maleic anhydride.

[0013] By using the above technical solution, the application selects EVA grafted maleic anhydride as the compatilizer in the case of determining the base composition, which can improve the compatibility of the base composition with inorganic components, is conducive to the uniform dispersion of magnesium hydroxide and antimony trioxide, and helps to improve the flame-retardant performance of the insulation material.

[0014] Preferably, the components of the base composition further include EVM rubber and ethylene-propylene rubber.

[0015] By using the above technical solution, on the basis of selecting EVA resin, the addition of EVM rubber and ethylene-propylene rubber can make the mechanical properties of the material qualified and have a certain margin, and on the other hand, EVM rubber and ethylene-propylene rubber are more easily radiation crosslinked than EVA resin, so that a more ideal crosslinking degree can be obtained under lower irradiation dose conditions.

[0016] Preferably, the light stabilizer includes hindered amine light stabilizer and benzotriazole light stabilizer.

[0017] By using the above technical solution, the hindered amine light stabilizer mainly reduces the damage to the insulation material caused by irradiation in the form of capturing free radicals generated by photo-oxidation, and the benzotriazole light stabilizer mainly reduces the damage to the insulation material caused by irradiation in the form of absorbing ultraviolet rays. The insulation material of the application can be crosslinked under lower radiation dose conditions, and the synergistic cooperation of the two light stabilizers can reduce the influence of irradiation on the flame-retardant performance and mechanical properties of the insulation material.

[0018] Preferably, the light stabilizer is composed of light stabilizer 944 and light stabilizer 326.

[0019] By using the above technical solution, the application preferably selects the specific types of hindered amine light stabilizer and benzotriazole light stabilizer, wherein the light stabilizer 326 not only has certain antioxidant properties itself, but also has synergistic effect when used with antioxidants, which can sufficiently reduce the thermal oxidative degradation of the insulation material during processing.

[0020] Preferably, the antioxidant includes hindered phenol antioxidant and phosphite antioxidant.

[0021] Preferably, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl) phosphite.

[0022] By adopting the technical scheme, the composition of the antioxidant is further optimized, and the two antioxidants can effectively reduce the thermal oxidative degradation of the insulating material in the processing process, and help to reduce the loss of mechanical properties of the insulating material in the processing process.

[0023] Preferably, the lubricant includes silicone powder, polyethylene wax and zinc stearate.

[0024] By adopting the technical scheme, the silicone powder, polyethylene wax and zinc stearate are used in combination to give the insulating material good lubricity, which helps to reduce the friction of the insulating material in the processing process, effectively reduces the energy consumption, and improves the production efficiency.

[0025] In a second aspect, the application provides a preparation method of a B1-grade flame-retardant irradiation cross-linked low-smoke halogen-free low-toxicity insulating material for braided wire, which adopts the following technical scheme.

[0026] A preparation method of a B1-grade flame-retardant irradiation cross-linked low-smoke halogen-free low-toxicity insulating material for braided wire, which includes the following steps:

[0027] (1) accurately weigh the base material composition, magnesium hydroxide, antimony trioxide, melamine cyanurate and additives according to the formula, and reserve;

[0028] (2) put the weighed magnesium hydroxide, antimony trioxide, melamine cyanurate and silane coupling agent in the high-speed mixer for stirring to obtain a flame-retardant composite;

[0029] (3) pass the antioxidant, light stabilizer, lubricant and part of the base material composition through the internal mixer, single-screw granulator, and then prepare the additive master batch after air cooling;

[0030] (4) put the flame-retardant composite, additive master batch, cross-linking sensitizer and remaining base material composition into the reciprocating mixer for mixing, and then perform cooling after single-screw extrusion granulation to obtain the B1-grade flame-retardant irradiation cross-linked low-smoke halogen-free low-toxicity insulating material for braided wire.

[0031] By adopting the technical scheme, after weighing the components, the magnesium hydroxide, antimony trioxide and melamine cyanurate are treated by using the silane coupling agent, which helps to reduce the agglomeration of the flame-retardant components and improve the dispersion effect of the flame-retardant components, so that the B1-grade flame-retardant double-braided cloth wire insulating material with low smoke, halogen-free and low toxicity and low combustion grade, combustion dripping grade and combustion heat release, good processing performance, self-extinguishing performance and insulation performance can be obtained.

[0032] In summary, the present application has the following advantages:

[0033] 1. The insulating material of the present application not only has low combustion grade, combustion dripping grade and combustion heat release, but also has good processing performance, self-extinguishing performance and insulation performance, which is more suitable for use in power facilities compared with the B1-grade cable material on the market.

[0034] 2. The composition of the base material composition is optimized. On the basis of selecting EVA resin, the addition of EVM rubber and ethylene-propylene rubber can make the mechanical properties of the material qualified and have a certain margin. On the other hand, EVM rubber and ethylene-propylene rubber are more easily radiation crosslinked than EVA resin, so that a more ideal crosslinking degree can be obtained under lower radiation dose conditions.

[0035] 3. Since the insulating material of the present application can be crosslinked under lower radiation dose conditions, and the hindered amine light stabilizer and benzotriazole light stabilizer are synergistically matched, the influence of radiation on the flame-retardant properties and mechanical properties of the insulating material can be sufficiently reduced. DETAILED DESCRIPTION

[0036] The present application will be further described in detail below in combination with examples and comparative examples. The raw materials involved in the present application can be obtained on the market.

[0037] Examples

[0038] Examples 1-5

[0039] The following will be described taking Example 1 as an example.

[0040] Example 1

[0041] The present embodiment provides a B1-grade flame-retardant double-braided cloth wire insulating material for radiation crosslinking, low smoke, halogen-free and low toxicity, which comprises the following components by weight: 100 kg of base material composition, 200 kg of magnesium hydroxide, 30 kg of antimony trioxide, 10 kg of melamine cyanurate and 9 kg of auxiliary. Among them, the model of magnesium hydroxide is PSF-150, which is provided by Shinoda Chemical, d 50 The particle size is 0.5 μm.

[0042] The base composition is composed of 50 kg of EVA resin, 20 kg of EVM rubber, 20 kg of ethylene propylene rubber and 10 kg of compatibilizer, which is EVA grafted maleic anhydride. The auxiliary agent is composed of 2 kg of silane coupling agent, 1 kg of antioxidant, 1 kg of crosslinking sensitizer, 1 kg of light stabilizer and 4 kg of lubricant, wherein the lubricant is composed of 1 kg of silicone powder, 2 kg of polyethylene wax and 1 kg of zinc stearate; the silane coupling agent is composed of silane coupling agent A172 and silane coupling agent S230 mixed in a weight ratio of 1:1; the antioxidant is composed of antioxidant 1010 and antioxidant 168 mixed in a weight ratio of 1:1; and the light stabilizer is composed of light stabilizer 944 and light stabilizer 326 mixed in a weight ratio of 1:1.

[0043] The embodiment provides a preparation method of a B1-grade flame-retardant double-braided cloth wire irradiation crosslinking low-smoke halogen-free low-toxicity insulating material, and the method comprises the following steps:

[0044] (1) accurately weigh the base composition, magnesium hydroxide, antimony trioxide, melamine cyanurate and auxiliary agent according to the formula, and reserve them;

[0045] (2) put the weighed magnesium hydroxide, antimony trioxide, melamine cyanurate and silane coupling agent in the auxiliary agent into a high-speed mixer and stir to obtain a flame-retardant compound;

[0046] (3) pass the antioxidant, light stabilizer, lubricant and 1 / 10 of the base composition in total weight of the base composition through a banbury mixer, a single-screw granulator, and then prepare an auxiliary agent master batch after air cooling;

[0047] (4) send the flame-retardant compound, the auxiliary agent master batch, the crosslinking sensitizer and the remaining base composition into a reciprocating mixer, and then perform cooling after single-screw extrusion granulation to obtain the B1-grade flame-retardant double-braided cloth wire irradiation crosslinking low-smoke halogen-free low-toxicity insulating material.

[0048] The main difference between Table 1 and Examples 1-5 is that the raw material ratios are different, the magnesium hydroxide d 50 in Examples 2-3 has a particle size of 0.7 μm, and the magnesium hydroxide d 50 in Examples 4-5 has a particle size of 1.0 μm.

[0049] Table 1 shows the raw material ratios and sources of the insulating material

[0050]

[0051]

[0052] Comparative Example

[0053] Comparative Example 1

[0054] The difference between this comparative example and Example 1 is that magnesium hydroxide (PSF-150, Jinshandai Chemical, d 50 is replaced by magnesium hydroxide (H-5, Umicore, d 50 particle size is 1.5 pm).

[0055] Comparative Example 2

[0056] The difference between this comparative example and Example 1 is that magnesium hydroxide (PSF-150, Jinshandai Chemical, d 50 is replaced by aluminum hydroxide (107 LEO, Umicore, d 50 particle size is 1.5 pm).

[0057] Comparative Example 3

[0058] The difference between this comparative example and Example 1 is that antimony trioxide and melamine cyanurate are removed on the basis of Example 1.

[0059] Comparative Example 4

[0060] The difference between this comparative example and Example 1 is that the amount of antimony trioxide is adjusted to 20 kg and the amount of melamine cyanurate is adjusted to 20 kg on the basis of Example 1.

[0061] Comparative Example 5

[0062] The difference between this comparative example and Example 1 is that the amount of magnesium hydroxide is adjusted to 190 kg and the light stabilizer is removed on the basis of Example 1.

[0063] Comparative Example 6

[0064] The difference between this comparative example and Example 1 is that the compatibilizer is changed from EVA grafted maleic anhydride to PE grafted maleic anhydride (grafting rate 1.2%) on the basis of Example 1.

[0065] Performance detection test method

[0066] According to relevant standards such as GB 31247-2014 Cable and Optical Cable Burning Performance Classification and GB / T 31248-2014 Test Method for Flame Spread, Heat Release and Smoke Production Characteristics of Cables or Optical Cables under Fire Conditions, the insulation material of each example and comparative example is processed into a sample, and is irradiated and crosslinked at a dose of 100 kGy. In addition, on the basis of Example 1, irradiation and crosslinking are carried out at a dose of 150 kGy, and this group is recorded as a control group. Then, the samples of Examples 1-5, Comparative Examples 1-6 and the control group are subjected to performance detection, and the results are shown in Tables 2 and 3.

[0067] Table 2 Detection data of examples

[0068]

[0069] Table 3 Test data of the comparative examples and the control group

[0070]

[0071]

[0072] It can be seen from the combination of Examples 1-5 and Comparative Examples 1-5 and in combination with Table 2 and Table 3 that the insulation material of Examples 1-5 has lower combustion grade, combustion drip grade and combustion heat release, and has better processing performance, self-extinguishing performance and insulation performance, and the overall performance is better than that of the insulation material of Comparative Examples 1-5. In Examples 1-5, the example with the addition of EVM rubber and ethylene-propylene rubber has lower carbonization height, maximum heat release rate and total heat release amount compared with the example without the addition of the two, which indicates that the addition of EVM rubber and ethylene-propylene rubber helps to further improve the flame retardant performance of the insulation material.

[0073] It can be seen from the combination of Example 1 and Comparative Example 1 and in combination with Table 2 and Table 3 that when the d 50 When the particle size of magnesium hydroxide does not meet the conditions defined in the present application, although the single vertical combustion test pass rate and the 2*2.5 double-stranded wire combustion grade do not change significantly, the carbonization height and the maximum heat release rate and the total heat release amount all increase significantly, which indicates that the d 50 The magnesium hydroxide with a particle size of 1.5 μm is not sufficient to fully improve the flame retardant performance of the insulation material, and the magnesium hydroxide with a particle size of 1.5 μm is not sufficient to fully improve the flame retardant performance of the insulation material.

[0074] It can be seen from the combination of Example 1 and Comparative Example 2 and in combination with Table 2 and Table 3 that the 2*2.5 double-stranded wire combustion grade, carbonization height, maximum heat release rate and total heat release amount measured in Comparative Example 2 all increase significantly, and the drip grade also increases to d1, which indicates that aluminum hydroxide is not sufficient to fully improve the flame retardant performance of the insulation material, and cannot make the insulation material meet the B1 level flame retardant requirement.

[0075] It can be seen from the combination of Example 1 and Comparative Example 3 and in combination with Table 2 and Table 3 that the single vertical combustion test pass rate measured in Comparative Example 3 decreases significantly compared with Example 1, and the carbonization height, maximum heat release rate, total heat release amount and drip grade all increase significantly, which indicates that in the absence of antimony trioxide and melamine cyanurate as flame retardant synergists, the flame retardant performance and self-extinguishing performance of the insulation material are not ideal.

[0076] It can be seen from the combination of Example 1 and Comparative Example 4 and in combination with Table 2 and Table 3 that the carbonization height, the maximum heat release rate, the total heat release amount, the dripping grade and the combustion gas conductivity measured for Comparative Example 4 all have a significant increase, indicating that when the antimony trioxide and melamine cyanurate are not added according to the formulation amount of the present application, the improvement of the flame retardant performance of the insulation material is limited, and the insulation material does not meet the B1 level flame retardant requirement. Moreover, due to the doubling of the amount of melamine cyanurate and the reduction of the amount of antimony trioxide by 1 / 3 (relative to Example 1), the toxicity index has a significant increase, which is difficult to meet the standard of low-toxicity wire.

[0077] It can be seen from the combination of Example 1 and Comparative Example 5 and in combination with Table 2 and Table 3 that the single vertical combustion test pass rate of Comparative Example 5 has a small decrease, and the carbonization height, the maximum heat release rate, the total heat release amount and the dripping grade all have a significant increase, indicating that the reduction of the amount of magnesium hydroxide and the removal of the light stabilizer are not conducive to fully improving the flame retardant performance of the insulation material, and also have a certain impact on the self-extinguishing performance.

[0078] It can be seen from the combination of Example 1 and Comparative Example 6 and in combination with Table 2 and Table 3 that the tensile strain at break of Comparative Example 6 is significantly lower than that of Example 1, and the carbonization height, the maximum heat release rate and the total heat release amount are all higher than those of Example 1. It can be seen that the flame retardant performance and part of the mechanical properties of the insulation material of Comparative Example 6 are poor, and it also indicates that EVA grafted maleic anhydride as a compatibilizer is more helpful to improve the mechanical properties and flame retardant performance of the insulation material.

[0079] It can be seen from the combination of Example 1 and the control group and in combination with Table 2 and Table 3 that the tensile strain at break of the control group is significantly lower than that of Example 1, and the carbonization height, the maximum heat release rate and the total heat release amount are all significantly higher than those of Example 1, and the dripping grade is also increased to d1. It can be seen that the flame retardant performance and part of the mechanical properties of the insulation material of the control group are poor, and it also indicates that a lower irradiation dose is helpful to obtain an insulation material with good mechanical properties and flame retardant performance.

[0080] The above examples are only an explanation of the present application and are not a limitation of the present application. Those skilled in the art can make modifications to the examples of the present application without creative contribution after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A B1-grade flame-retardant twisted-pair electrical wire insulation material, characterized in that, The composition comprises the following components in parts by weight: 80-100 parts of base composition, 180-220 parts of magnesium hydroxide, 20-50 parts of antimony trioxide, 9.5-10.5 parts of melamine cyanurate, and 9-10 parts of additives, including silane coupling agents, antioxidants, crosslinking sensitizers, lubricants, and light stabilizers. The base composition comprises EVA resin and a compatibilizer. The magnesium hydroxide has a d... 50 The particle size is 0.5-1μm; the compatibilizer is EVA grafted with maleic anhydride; the components of the base composition also include EVM rubber and ethylene propylene rubber; the lubricant includes silicone powder, polyethylene wax and zinc stearate; The preparation method of the B1-grade flame-retardant twisted-pair cloth wire irradiation cross-linked low-smoke halogen-free low-toxicity insulation material includes the following steps: (1) Accurately weigh the base material composition, magnesium hydroxide, antimony trioxide, melamine cyanurate and additives according to the formula, and set aside; (2) Weigh the magnesium hydroxide, antimony trioxide, melamine cyanurate and silane coupling agent in the additives and stir them together in a high-speed mixer to obtain a flame retardant composite. (3) The antioxidant, light stabilizer, lubricant and some base material composition are mixed and granulated by a single screw, and then cooled by air to obtain the additive masterbatch. (4) The flame retardant compound, additive masterbatch, crosslinking sensitizer and the remaining base material composition are fed into a reciprocating machine for mixing, and then granulated by single screw extrusion and cooled to obtain B1 grade flame retardant twisted pair cloth wire irradiated crosslinked low smoke halogen-free low toxicity insulation material.

2. The B1-grade flame-retardant twisted-pair electrical wire irradiation cross-linked low-smoke halogen-free low-toxicity insulation material according to claim 1, characterized in that, The amount of EVA resin used accounts for 40-87.5% of the total weight of the base composition.

3. The B1-grade flame-retardant twisted-pair electrical wire irradiation cross-linked low-smoke halogen-free low-toxicity insulation material according to claim 1, characterized in that, The light stabilizers include hindered amine light stabilizers and benzotriazole light stabilizers.

4. The B1-grade flame-retardant twisted-pair electrical wire irradiation cross-linked low-smoke halogen-free low-toxicity insulation material according to claim 3, characterized in that, The light stabilizer is composed of light stabilizer 944 and light stabilizer 326.

5. The B1-grade flame-retardant twisted-pair electrical wire irradiation cross-linked low-smoke halogen-free low-toxicity insulation material according to claim 4, characterized in that, The antioxidants include hindered phenolic antioxidants and phosphite antioxidants.

6. The B1-grade flame-retardant twisted-pair electrical wire irradiation cross-linked low-smoke halogen-free low-toxicity insulation material according to claim 5, characterized in that, The antioxidants are pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl) phosphite.

7. The method for preparing the B1-grade flame-retardant twisted-pair insulation material for electrical wires by irradiation cross-linking, low-smoke, halogen-free, and low-toxicity insulation according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Accurately weigh the base material composition, magnesium hydroxide, antimony trioxide, melamine cyanurate and additives according to the formula, and set aside; (2) Weigh the magnesium hydroxide, antimony trioxide, melamine cyanurate and silane coupling agent in the additives and stir them together in a high-speed mixer to obtain a flame retardant composite. (3) The antioxidant, light stabilizer, lubricant and some base material composition are mixed and granulated by a single screw, and then cooled by air to obtain the additive masterbatch. (4) The flame retardant compound, additive masterbatch, crosslinking sensitizer and the remaining base material composition are fed into a reciprocating machine for mixing, and then granulated by single screw extrusion and cooled to obtain B1 grade flame retardant twisted pair cloth wire irradiated crosslinked low smoke halogen-free low toxicity insulation material.

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