Preparation method of cable with fireproof and flame-retardant functions

Abstract

The invention discloses a preparation method of a cable with fireproof and flame-retardant functions. A sheath material of the cable is prepared from the following raw materials in parts by weight: 45 to 65 parts of polyphenylene sulfide, 10 to 14 parts of a phosphorus-nitrogen flame retardant, 12 to 18 parts of modified nano magnesium hydroxide, 1.5 to 4 parts of graphene, 3 to 6 parts of carbon nanotubes, 1.5 to 2.5 parts of a silane coupling agent, 0.8 to 1.5 parts of a lubricant, 0.5 to 0.8 part of an antioxidant and 1.2 to 1.8 parts of a cross-linking agent. According to the preparation method of the cable with the fireproof and flame-retardant functions, the flame-retardant efficiency of the cable is remarkably improved by compounding a phosphorus-nitrogen flame retardant, ammonium polyphosphate and melamine cyanurate in a mass ratio of (3.5: 1)-(4.5: 1), modifying with nano magnesium hydroxide and surface stearic acid, and combining with the synergistic effect of graphene oxide and carbon nanotubes, so that the flame-retardant efficiency of the cable is greatly improved, and the flame-retardant performance of the cable is improved. And the phosphorus-nitrogen flame retardant generates an expanded carbon layer during combustion to isolate oxygen and combustible gas, and the nano magnesium hydroxide absorbs heat through decomposition to reduce the combustion temperature and release crystal water to dilute the combustible gas at the same time.

Description

Technical Field

[0001] The present invention relates to the field of cable preparation methods, and in particular to a method for preparing a cable with fire-retardant functions. Background Art

[0002] Traditional fire-resistant cables often use a single flame retardant (such as aluminum hydroxide), requiring a large amount (≥40%) to meet flame retardancy standards, resulting in a decrease in the material's mechanical properties. Furthermore, base materials such as polyethylene lack heat resistance (heat deformation temperature < 200°C) and are prone to softening and deformation at high temperatures, affecting the cable's long-term stability.

[0003] Chinese patent announcement number CN108276693A discloses a cable material with fireproof function and its preparation method. The cable material has a scientific formula, and the formula ingredients contain: styrene-ethylene-butylene benzene-ethylene, hydrogenated styrene-butadiene-styrene copolymer, maleic anhydride grafted polyethylene, dodecanedioic acid, flame retardant, inorganic filler, magnesia, bentonite, crosslinking agent, fireproof foam, and compatibilizer. The above ingredients work synergistically, making the prepared cable material have a fireproof and flame-retardant effect that is superior to existing cable materials.

[0004] In the actual production process of the formula in the above patent document, the dosage of polyphenylene sulfide (PPS) ranges from 40 to 70 parts. The range is too wide and may cause fluctuations in material properties. In addition, the compounding ratio of phosphorus-nitrogen flame retardants (3:1-5:1) spans a large range, which may affect the flame retardant efficiency. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for preparing a fire-resistant and flame-retardant cable, which can effectively solve the problems in the background technology.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A fire-retardant cable, comprising a sheath and a core wire, wherein the sheath is wrapped around the core wire, and the sheath material of the cable comprises the following raw materials in parts by weight:

[0008] 45-65 parts of polyphenylene sulfide, 10-14 parts of phosphorus-nitrogen flame retardant, 12-18 parts of modified nano-magnesium hydroxide, 1.5-4 parts of graphene, 3-6 parts of carbon nanotubes, 1.5-2.5 parts of silane coupling agent, 0.8-1.5 parts of lubricant, 0.5-0.8 parts of antioxidant, and 1.2-1.8 parts of cross-linking agent.

[0009] Preferably, the phosphorus-nitrogen flame retardant is compounded by ammonium polyphosphate and melamine cyanurate in a mass ratio of 3.5:1-4.5:1.

[0010] Preferably, the particle size of the modified nano-magnesium hydroxide is 60-90 nm, and the surface is modified with stearic acid, and the amount of the modifier added is 2-5% of the mass of the nano-magnesium hydroxide.

[0011] Preferably, the graphene is graphene oxide, and its specific surface area is 600-750m 2 / g, number of layers ≤ 5 layers.

[0012] Preferably, the lubricant is a mixture of vinyl bisstearamide and polyethylene wax in a mass ratio of 1:1-2:1.

[0013] Preferably, the cross-linking agent is dicumyl peroxide, and the added amount is 0.8-1.5% of the total mass of the sheath material.

[0014] The present invention also discloses a method for preparing a fire-retardant cable. The method for preparing the sheath material comprises the following steps:

[0015] Step 1: premixing nano magnesium hydroxide and silane coupling agent in a high-speed mixer for 10-15 minutes at a mixing temperature of 60-80° C. to obtain modified nano magnesium hydroxide;

[0016] Step 2: Mix polyphenylene sulfide, phosphorus-nitrogen flame retardant, graphene, carbon nanotubes, lubricant, antioxidant, crosslinking agent with modified nano magnesium hydroxide in step 1, and melt blend in a twin-screw extruder at an extrusion temperature of 290-310° C., a screw speed of 250-350 rpm, and a residence time of 2-4 minutes;

[0017] Step 3: pelletizing the extruded material through water cooling and drying to a moisture content of ≤0.1% to obtain sheath material particles;

[0018] Step 4: The sheath material particles are coated on the core wire surface through a cable extruder. The extruder die temperature is 300-320°C and the cooling water temperature is 20-30°C to form a fire-retardant cable.

[0019] Step 5: Prepare sheath material particles according to steps 1 to 3;

[0020] The core wire is preheated to 90-110℃, and the sheath material particles are coated on the core wire surface using a cable extruder. The temperatures of each zone of the extruder are: zone 1 280-290℃, zone 2 300-310℃, zone 3 305-315℃, and die head 310-320℃. After cooling, the cable is reeled up to obtain a finished cable.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention significantly improves the flame retardant efficiency of the cable by compounding a phosphorus-nitrogen flame retardant (ammonium polyphosphate and melamine cyanurate mass ratio of 3.5:1-4.5:1) and modified nano-magnesium hydroxide (surface modified with stearic acid), combined with the synergistic effect of graphene oxide and carbon nanotubes.

[0023] 2. The present invention generates an expanded carbon layer during combustion by the phosphorus-nitrogen flame retardant to isolate oxygen and combustible gas. Nano magnesium hydroxide absorbs heat by decomposition to reduce the combustion temperature and releases crystal water to dilute the combustible gas.

[0024] 3. The present invention forms a dense carbon layer through graphene and carbon nanotubes to further block heat transfer. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the 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.

[0026] The present application prepares a fire-retardant cable in the following manner:

[0027] The preparation method of the sheath material comprises the following steps:

[0028] Step 1: premixing nano magnesium hydroxide and silane coupling agent in a high-speed mixer for 10-15 minutes at a mixing temperature of 60-80° C. to obtain modified nano magnesium hydroxide;

[0029] Step 2: Mix polyphenylene sulfide, phosphorus-nitrogen flame retardant, graphene, carbon nanotubes, lubricant, antioxidant, crosslinking agent with modified nano magnesium hydroxide in step 1, and melt blend in a twin-screw extruder at an extrusion temperature of 290-310° C., a screw speed of 250-350 rpm, and a residence time of 2-4 minutes;

[0030] Step 3: pelletizing the extruded material through water cooling and drying to a moisture content of ≤0.1% to obtain sheath material particles;

[0031] Step 4: The sheath material particles are coated on the core wire surface through a cable extruder. The extruder die temperature is 300-320°C and the cooling water temperature is 20-30°C to form a fire-retardant cable.

[0032] Step 5: Prepare sheath material particles according to steps 1 to 3;

[0033] The core wire is preheated to 90-110℃, and the sheath material particles are coated on the core wire surface using a cable extruder. The temperatures of each zone of the extruder are: zone 1 280-290℃, zone 2 300-310℃, zone 3 305-315℃, and die head 310-320℃. After cooling, the cable is reeled up to obtain a finished cable.

[0034] Example 1: The cable sheath material with fire retardant function prepared in this example comprises the following raw materials in parts by weight:

[0035] Polyphenylene sulfide: 55 parts, phosphorus-nitrogen flame retardant: 11 parts, modified nano-magnesium hydroxide: 15 parts, graphene oxide: 2.5 parts, carbon nanotubes: 4 parts, silane coupling agent: 2 parts, lubricant: 1.2 parts, antioxidant: 0.6 parts, cross-linking agent: 1.5 parts.

[0036] Example 2: A fire-retardant cable sheath material formulation, wherein the raw materials include, by weight:

[0037] Polyphenylene sulfide: 60 parts, phosphorus-nitrogen flame retardant: 12 parts, modified nano-magnesium hydroxide: 14 parts, graphene oxide: 3 parts, carbon nanotubes: 5 parts, silane coupling agent: 2.3 parts, lubricant: 1 part, antioxidant: 0.7 parts, cross-linking agent: 1.6 parts.

[0038] Example 3: A fire-retardant cable sheath material formula, wherein the raw materials include, by weight:

[0039] Polyphenylene sulfide: 52 parts, phosphorus-nitrogen flame retardant: 11 parts, modified nano-magnesium hydroxide: 15 parts, graphene oxide: 1 part, carbon nanotubes: 4.5 parts, silane coupling agent: 2 parts, lubricant: 1 part, antioxidant: 0.7 parts, cross-linking agent: 1.4 parts.

[0040] Example 4: A formula for a cable sheath material with fire retardant properties, wherein the raw materials include, by weight:

[0041] Polyphenylene sulfide: 54 parts, phosphorus-nitrogen flame retardant: 12 parts, modified nano-magnesium hydroxide: 18 parts, graphene oxide: 3 parts, carbon nanotubes: 4 parts, silane coupling agent: 2.3 parts, lubricant: 1.5 parts, antioxidant: 0.7 parts, cross-linking agent: 1.8 parts.

[0042] Example 5: A formula for a cable sheath material with fire retardant properties, wherein the raw materials include, by weight:

[0043] Polyphenylene sulfide: 50 parts, phosphorus-nitrogen flame retardant: 10 parts, modified nano-magnesium hydroxide: 16 parts, graphene oxide: 2 parts, carbon nanotubes: 3.5 parts, silane coupling agent: 1.8 parts, lubricant: 0.9 parts, antioxidant: 0.5 parts, cross-linking agent: 1.3 parts.

[0044] Comparative Example 1

[0045] A fire-retardant cable sheath material formula, the raw materials of which include, by weight:

[0046] Polyphenylene sulfide: 55 parts, phosphorus-nitrogen flame retardant: 11 parts, modified nano-magnesium hydroxide: 15 parts, graphene oxide: 2.5 parts, carbon nanotubes: 4 parts, silane coupling agent: 2 parts, lubricant: 1.2 parts, antioxidant: 0.6 parts, cross-linking agent: 1.5 parts.

[0047] The phosphorus-nitrogen flame retardant is prepared by compounding ammonium polyphosphate and melamine cyanurate in a mass ratio of 3.5:1-4.5:1.

[0048] The particle size of the modified nano magnesium hydroxide is 60-90 nm, and the surface is modified by stearic acid. The amount of the modifier added is 2-5% of the mass of the nano magnesium hydroxide.

[0049] The graphene is graphene oxide, and its specific surface area is 600-750m 2 / g, number of layers ≤ 5 layers.

[0050] The lubricant is a mixture of vinyl bisstearamide and polyethylene wax in a mass ratio of 1:1-2:1.

[0051] The cross-linking agent is dicumyl peroxide, and the added amount is 0.8-1.5% of the total mass of the sheath material.

[0052] The following preparation method of a cable sheath with fire retardant function can be obtained from the above comparative examples:

[0053] 1. Nano magnesium hydroxide premix modification:

[0054] Nano magnesium hydroxide and silane coupling agent were added into a high-speed mixer (rotation speed 800 rpm) in proportion, heated to 70° C., and premixed for 12 minutes to allow the silane coupling agent to evenly coat the particle surface to form a hydrophobic layer.

[0055] 2. Raw material premixing and melt extrusion:

[0056] PPS particles, phosphorus-nitrogen flame retardant, graphene oxide, carbon nanotubes, lubricant, antioxidant, DCP and modified nano magnesium hydroxide were added to a twin-screw extruder (L / D=40);

[0057] Zone temperature control: Zone 1 290°C (preheating and plasticizing), Zone 2 300°C (melting and mixing), Zone 3 305°C (homogenization), screw speed 300rpm, residence time 3 minutes, to ensure that the material is fully melted and dispersed.

[0058] 3. Granulation and drying:

[0059] The extruded material strands were cooled in a water trough (water temperature 25° C.) and then pelletized. The pellets were dried in a hot air oven (80° C., 4 hours) until the moisture content was ≤0.1%.

[0060] 4. Cable extrusion molding:

[0061] Copper conductor (cross-sectional area 2.5mm 2 ) is preheated to 100°C, and the sheath material particles are passed through a single-screw extruder (die head temperature 315°C) to coat the conductor surface. The extrusion speed is 15m / min and the cooling water temperature is 25°C.

[0062] Comparative Example 2

[0063] A fire-retardant cable sheath material formula, the raw materials of which include, by weight:

[0064] Polyphenylene sulfide: 60 parts, phosphorus-nitrogen flame retardant: 12 parts, modified nano-magnesium hydroxide: 14 parts, graphene oxide: 3 parts, carbon nanotubes: 5 parts, silane coupling agent: 2.3 parts, lubricant: 1 part, antioxidant: 0.7 parts, cross-linking agent: 1.6 parts.

[0065] The phosphorus-nitrogen flame retardant is prepared by compounding ammonium polyphosphate and melamine cyanurate in a mass ratio of 3.5:1-4.5:1.

[0066] The particle size of the modified nano magnesium hydroxide is 60-90 nm, and the surface is modified by stearic acid. The amount of the modifier added is 2-5% of the mass of the nano magnesium hydroxide.

[0067] The graphene is graphene oxide, and its specific surface area is 600-750m 2 / g, number of layers ≤ 5 layers.

[0068] The lubricant is a mixture of vinyl bisstearamide and polyethylene wax in a mass ratio of 1:1-2:1.

[0069] The cross-linking agent is dicumyl peroxide, and the added amount is 0.8-1.5% of the total mass of the sheath material.

[0070] The following preparation method of a cable sheath with fire retardant function can be obtained from the above comparative examples:

[0071] 1. Nano magnesium hydroxide premix:

[0072] At 65°C, nano magnesium hydroxide and silane coupling agent were premixed for 15 minutes (rotation speed 1000 rpm). After modification, the surface contact angle of the particles was ≥120°, thereby improving the interfacial compatibility with PPS.

[0073] 2. Melt blending and extrusion:

[0074] Twin-screw extruder zone temperature: zone 1 295°C, zone 2 305°C, zone 3 310°C, screw speed 280 rpm, residence time 3.5 minutes;

[0075] The extruded strands were water-cooled and pelletized, and then vacuum-dried (70° C., 6 hours) to a moisture content of ≤0.08%.

[0076] 3. Cable forming process:

[0077] The aluminum core wire (multi-strand twisted structure) was preheated to 110°C, and the sheath material was coated through an extruder die (temperature 318°C) with a line speed of 12 m / min and a cooling water temperature of 28°C.

[0078] Comparative Example 3

[0079] A fire-retardant cable sheath material formula, the raw materials of which include, by weight:

[0080] Polyphenylene sulfide: 50 parts, phosphorus-nitrogen flame retardant: 10 parts, modified nano-magnesium hydroxide: 16 parts, graphene oxide: 2 parts, carbon nanotubes: 3.5 parts, silane coupling agent: 1.8 parts, lubricant: 0.9 parts, antioxidant: 0.5 parts, cross-linking agent: 1.3 parts.

[0081] The phosphorus-nitrogen flame retardant is prepared by compounding ammonium polyphosphate and melamine cyanurate in a mass ratio of 3.5:1-4.5:1.

[0082] The particle size of the modified nano magnesium hydroxide is 60-90 nm, and the surface is modified by stearic acid. The amount of the modifier added is 2-5% of the mass of the nano magnesium hydroxide.

[0083] The graphene is graphene oxide, and its specific surface area is 600-750m 2 / g, number of layers ≤ 5 layers.

[0084] The lubricant is a mixture of vinyl bisstearamide and polyethylene wax in a mass ratio of 1:1-2:1.

[0085] The cross-linking agent is dicumyl peroxide, and the added amount is 0.8-1.5% of the total mass of the sheath material.

[0086] The following preparation method of a cable sheath with fire retardant function can be obtained from the above comparative examples:

[0087] 1. Premixing and modification:

[0088] Nano-magnesium hydroxide was premixed at 75°C for 10 minutes (rotation speed 900 rpm). After modification, the surface Zeta potential of the particles decreased from +25 mV to -15 mV, reducing agglomeration.

[0089] 2. Extrusion and granulation:

[0090] Twin-screw extruder temperature: zone 1 285°C, zone 2 300°C, zone 3 308°C, screw speed 320 rpm, residence time 2.8 minutes;

[0091] The extruded granules were fluidized bed dried (60°C, 5 hours) to a moisture content of 0.07%.

[0092] 3. Cable production:

[0093] The tinned copper core wire was preheated to 90°C, and the sheath material was extruded through a die (temperature 312°C) at a line speed of 18 m / min and a cooling water temperature of 22°C.

[0094] The oxygen index (%), tensile strength (MPa), heat deformation temperature (°C), and smoke density (Ds) of Examples 1 to 5 and Comparative Examples 1 to 3 were obtained by the following method:

[0095] Test method and basis of oxygen index (%):

[0096] Standard method: ASTM D2863 "Plastics Combustion Performance Test-Oxygen Index Method";

[0097] Test equipment: oxygen index meter (such as FTT oxygen index meter);

[0098] step:

[0099] Sample preparation: The sheath material was made into a strip sample of 80 mm × 10 mm × 4 mm;

[0100] Test conditions: Fix the sample vertically in the combustion tube, adjust the oxygen / nitrogen ratio, and set the initial oxygen concentration according to the estimate;

[0101] Ignition and judgment: Use a propane flame to ignite the top of the sample and observe the burning time and damage length. If the burning time is greater than 30 seconds or the damage length is greater than 50 mm, reduce the oxygen concentration; otherwise, increase it. The final oxygen index is the minimum oxygen concentration percentage required to maintain flame combustion for 3 minutes or damage 50 mm.

[0102] Data recording: Take the average value of 5 samples, accurate to 0.1%.

[0103] Test method and basis of tensile strength (MPa):

[0104] Standard method: ASTM D638 "Standard test method for tensile properties of plastics";

[0105] Testing equipment: universal material testing machine (such as Instron5967);

[0106] step:

[0107] Sample preparation: The sheath material was injection molded into a standard dumbbell-shaped specimen (Type I, gauge section size: 57 mm × 13 mm × 3 mm);

[0108] Test conditions: clamp spacing 50 mm, tensile rate 50 mm / min, ambient temperature 23 ± 2 °C;

[0109] Test process: Clamp the two ends of the specimen and stretch it at a constant speed until it breaks. Record the maximum load (F) and the cross-sectional area of the specimen (A).

[0110] Calculation formula: Tensile strength (MPa) = maximum load (N) / cross-sectional area (mm 2 ).

[0111] Test method and basis of heat deformation temperature (℃):

[0112] Standard method: ISO75-2 "Determination of deflection temperature of plastics under load - Part 2: Plastics and hard rubber";

[0113] Testing equipment: thermal deformation testing machine (such as Ceast HDT3 Vicat);

[0114] step:

[0115] Sample preparation: The sheath material is made into a rectangular specimen of 80 mm × 10 mm × 4 mm;

[0116] Test conditions: three-point bending loading method, span 64mm, load 0.45MPa (or 1.80MPa);

[0117] Heating program: Heat the silicone oil bath at a rate of 120°C / h and record the temperature at which the bending deformation of the specimen reaches 0.34 mm, which is the heat deformation temperature;

[0118] Data recording: Take the average value of 3 samples, with a deviation of ≤2°C.

[0119] Test method and basis of smoke density (Ds):

[0120] Standard method: GB / T17651.2-2021 "Determination of smoke density of electrical and optical cables burning under specific conditions - Part 2: Test procedures and requirements";

[0121] Test equipment: smoke density chamber (such as FTT smoke density tester);

[0122] step:

[0123] Sample preparation: The sheath material is made into a square specimen of 75mm×75mm×3mm;

[0124] Test conditions: The sample is placed horizontally in the combustion chamber, the flame power is 50kW, and the radiation cone temperature is about 600℃;

[0125] Data collection: After igniting the sample, the attenuation of the light transmittance of the smoke is measured using a laser light source and a photoelectric sensor, and the data is recorded continuously for 20 minutes.

[0126] Calculation formula: smoke density (Ds) = (1-T_min / T_0) × 100%, where T_min is the minimum transmittance and T_0 is the initial transmittance.

[0127] The performance test results of the cables of comparative examples 1-3 are as follows:

[0128]

[0129]

[0130] As can be seen from the above table, the flame retardancy (oxygen index ≥ 38%), mechanical strength (tensile strength ≥ 46 MPa) and low smoke characteristics (smoke density ≤ 48) of the cable of the present invention are significantly better than those of traditional products.

[0131] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A fire-retardant cable, comprising a sheath and a core wire, wherein the sheath is wrapped around the core wire, characterized in that: The sheath material of the cable comprises the following raw materials in parts by weight: 45-65 parts of polyphenylene sulfide, 10-14 parts of phosphorus-nitrogen flame retardant, 12-18 parts of modified nano-magnesium hydroxide, 1.5-4 parts of graphene, 3-6 parts of carbon nanotubes, 1.5-2.5 parts of silane coupling agent, 0.8-1.5 parts of lubricant, 0.5-0.8 parts of antioxidant, and 1.2-1.8 parts of cross-linking agent.

2. The fire-retardant cable according to claim 1, characterized in that: The phosphorus-nitrogen flame retardant is prepared by compounding ammonium polyphosphate and melamine cyanurate in a mass ratio of 3.5:1-4.5:

1.

3. The fire-retardant cable according to claim 1, characterized in that: The particle size of the modified nano magnesium hydroxide is 60-90 nm, and the surface is modified by stearic acid. The amount of the modifier added is 2-5% of the mass of the nano magnesium hydroxide.

4. The fire-retardant cable according to claim 1, characterized in that: The graphene is graphene oxide, and its specific surface area is 600-750m 2 / g, number of layers ≤ 5 layers.

5. The fire-retardant cable according to claim 1, characterized in that: The lubricant is a mixture of vinyl bisstearamide and polyethylene wax in a mass ratio of 1:1-2:

1.

6. The fire-retardant cable according to claim 1, characterized in that: The cross-linking agent is dicumyl peroxide, and the added amount is 0.8-1.5% of the total mass of the sheath material.

7. A method for preparing a fire-retardant cable according to any one of claims 1 to 6, characterized in that: The preparation method of the sheath material comprises the following steps: Step 1: premixing nano magnesium hydroxide and silane coupling agent in a high-speed mixer for 10-15 minutes at a mixing temperature of 60-80° C. to obtain modified nano magnesium hydroxide; Step 2: Mix polyphenylene sulfide, phosphorus-nitrogen flame retardant, graphene, carbon nanotubes, lubricant, antioxidant, crosslinking agent with modified nano magnesium hydroxide in step 1, and melt blend in a twin-screw extruder at an extrusion temperature of 290-310° C., a screw speed of 250-350 rpm, and a residence time of 2-4 minutes; Step 3: pelletizing the extruded material through water cooling and drying to a moisture content of ≤0.1% to obtain sheath material particles; Step 4: The sheath material particles are coated on the core wire surface through a cable extruder. The extruder die temperature is 300-320°C and the cooling water temperature is 20-30°C to form a fire-retardant cable. Step 5: Prepare sheath material particles according to steps 1 to 3; The core wire is preheated to 90-110℃, and the sheath material particles are coated on the core wire surface using a cable extruder. The temperatures of each zone of the extruder are: zone 1 280-290℃, zone 2 300-310℃, zone 3 305-315℃, and die head 310-320℃. After cooling, the cable is reeled up to obtain a finished cable.

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