Flame-retardant cable material for new energy charging pile

Abstract

The application provides a new energy charging pile flame-retardant cable material, which comprises the following raw materials in parts by weight: halogen-free crosslinked polyolefin 80-100 parts, modified polyphenylene sulfide 30-40 parts, composite plasticizer 20-25 parts, nano flame retardant 10-15 parts and compatible solvent 5-10 parts. The preparation of the modified polyphenylene sulfide comprises the following steps: drying polyphenylene sulfide particles, adding styrene-ethylene-butylene-styrene block copolymer and acetyl citrate trioctyl ester into a high-speed mixer and uniformly mixing, passing mixed gas, generating plasma under the action of high-frequency electromagnetic oscillation, passing nitrogen to restore normal pressure, and extruding and granulating by a double-screw extruder in a segmented temperature control mode to obtain the modified polyphenylene sulfide. The flame-retardant cable material prepared from the material has strong thermal stability, various components are compatible, and synergistic effect is achieved, so that the new energy charging cable material obtained meets the daily use requirements of the cable material for new energy charging piles and has application effect.

Description

Technical Field

[0001] This invention relates to the field of flame-retardant cable materials technology, and in particular to a flame-retardant cable material for new energy charging piles. Background Technology

[0002] New energy green travel is a new mode of transportation, and the safety of charging stations has become a major concern. Standard electric vehicle DC / AC charging stations are being built extensively. During the charging process, new energy charging stations have specific requirements for signal control and transmission network systems related to voltage and current. Currently, new energy charging stations with high voltage resistance, high temperature resistance, electromagnetic interference resistance, and stable signal transmission better meet market demands. However, the cable materials used in new energy charging stations have drawbacks such as insufficient tensile strength and poor flame retardancy and heat resistance. While traditional polyvinyl chloride (PVC) materials are inexpensive, have simple manufacturing processes, and a high oxygen index, they also have some disadvantages, including poor high-temperature resistance, potential fire hazards, the presence of phthalate plasticizers (compliance with REACH regulations), environmental unfriendliness, and the potential for leaching from the large amounts of liquid plasticizers. Summary of the Invention

[0003] In view of this, the present invention provides a flame-retardant cable material for new energy charging piles to meet the charging needs of new energy.

[0004] The technical solution of this invention is implemented as follows: A flame-retardant cable material for new energy charging piles comprises the following raw materials in parts by weight: 80-100 parts of low-smoke halogen-free irradiated crosslinked polyolefin, 30-40 parts of modified polyphenylene sulfide, 20-25 parts of composite plasticizer, 10-15 parts of nano flame retardant, and 5-10 parts of compatibilizer; the preparation of the modified polyphenylene sulfide includes the following steps: S1: Dry the polyphenylene sulfide particles to reduce their moisture content to less than 3% to obtain dried polyphenylene sulfide particles. S2: Add the dried polyphenylene sulfide particles, styrene-ethylene-butene-styrene block copolymer, and trioctyl acetyl citrate to a high-speed mixer and mix evenly to obtain mixture I; S3: Mixture I is introduced into a mixed gas. Under the action of high-frequency electromagnetic oscillation, plasma is generated. Nitrogen gas is introduced to restore normal pressure. The mixture is then sealed in a dry environment to obtain mixture II. S4: Mixture II is extruded and granulated in stages using a twin-screw extruder under controlled temperature to obtain modified polyphenylene sulfide.

[0005] Furthermore, in step S1, the drying temperature is 120-125℃ and the drying time is 3-5 hours.

[0006] Furthermore, in step S2, the mass ratio of the dried polyphenylene sulfide particles to the styrene-ethylene-butene-styrene block copolymer and trioctyl acetyl citrate is 80-100:15-20:5-10.

[0007] Furthermore, in step S3, the mixed gas is argon and oxygen in a mass ratio of 4-6:1, and the gas flow rate is 20-50 sccm.

[0008] Furthermore, in step S3, the radio frequency power of the high-frequency electromagnetic oscillation is 100-120W, the electrode spacing is 10-20 mm, and the time is 3-6 min.

[0009] Furthermore, in step S4, the temperature of the feeding section is 150-170℃, the temperature of the melting section is 290-310℃, the temperature of the homogenization section is 280-300℃, the initial screw speed is 40-50 r / min, the speed during production is 250-300 r / min, the back pressure is 18-22 MPa, and the die head pressure is 60-80 MPa.

[0010] Furthermore, the low-smoke halogen-free irradiated crosslinked polyolefin is composed of 45-55 parts by weight of linear low-density polyethylene, 5-10 parts of ethylene-vinyl acetate copolymer, 25-30 parts of aluminum hydroxide, 10-15 parts of magnesium hydroxide, 1-3 parts of silicone resin, 1-2 parts of triallyl isocyanurate, 0.5-1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1-2 parts of zinc stearate, and 1-3 parts of zinc molybdate.

[0011] Furthermore, the nano flame retardant includes one of layered nano zirconium phosphate, carbon nanotubes, nano magnesium hydroxide, and nano aluminum hydroxide.

[0012] Furthermore, the composite plasticizer includes at least one of dioctyl phthalate, trioctyl acetyl citrate, and tributyl acetyl citrate; the solvent is maleic anhydride-grafted ethylene-octene copolymer.

[0013] The preparation steps of flame-retardant cable material include: mixing low-smoke halogen-free irradiated cross-linked polyolefin and modified polyphenylene sulfide, sealing and stirring after purging with nitrogen, stirring at a temperature of 45-55℃ and a speed of 200-300 rpm for 20-25 minutes, adding a solvent, purging with nitrogen again and sealing, raising the temperature to 55-60℃, increasing the speed to 400-500 rpm, and stirring for 20-25 minutes to obtain a mixture; adding a composite plasticizer and a nano flame retardant to the mixture, raising the temperature to 65-75℃, stirring evenly at a speed of 400-500 rpm, extruding and molding, cooling and granulating to obtain cable material for new energy charging piles.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention relates to a flame-retardant cable material for new energy charging piles. It features enhanced thermal stability, excellent flame-retardant effect, and good tensile strength, meeting the daily usage requirements of cables for new energy charging piles and possessing application value. The addition of modified polyphenylene sulfide to the raw materials enhances the flame-retardant effect of the cable material, provides good thermal stability, and improves high-temperature resistance, reducing the potential hazards of cable materials being unable to withstand high temperatures. Detailed Implementation

[0015] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention. Unless otherwise specified, the experimental methods used in the embodiments of this invention are conventional methods.

[0016] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0017] The manufacturer of the styrene-ethylene-butene-styrene block copolymer is Dongguan Huibai Plastic Raw Materials Co., Ltd., grade 7131; the manufacturer of the ethylene-vinyl acetate copolymer is Guangzhou Binlong Chemical Co., Ltd., model UL15028, with a tensile strength of 6.5 MPa and an elongation of 700%.

[0018] Preparation Example 1 The preparation of modified polyphenylene sulfide includes the following steps: Step (1): Dry the polyphenylene sulfide particles at a temperature of 120°C for 3 hours. After drying, the moisture content should be less than 3% to obtain dried polyphenylene sulfide particles. Step (2): Add the dried polyphenylene sulfide particles with a mass ratio of 80:15:5, styrene-ethylene-butene-styrene block copolymer, and trioctyl acetyl citrate to a high-speed mixer and mix them evenly to obtain mixture I; Step (3): Mixture I is introduced into a mixed gas, which is argon and oxygen in a mass ratio of 4:1 and the gas flow rate is 20 sccm. After the mixed gas is introduced, plasma is generated under the action of high-frequency electromagnetic oscillation. The radio frequency power of the high-frequency electromagnetic oscillation is 100W, the electrode spacing is 10 mm, and the time is 3min. After nitrogen is introduced again, the pressure is restored to normal and sealed in a dry environment to obtain mixture II. Step (4): Mixture II is extruded and granulated in stages by a twin-screw extruder under controlled temperature. During granulation, the temperature of the feed section of the twin-screw is 150℃, the temperature of the melting section is 290℃, the temperature of the homogenization section is 280℃, the initial screw speed is 40 r / min, the speed during production is 250 r / min, the back pressure is 18 MPa, and the die head pressure is 60 MPa. After extrusion granulation, modified polyphenylene sulfide is obtained.

[0019] Preparation Example 2 The preparation of modified polyphenylene sulfide includes the following steps: Step (1): Dry the polyphenylene sulfide particles at a temperature of 125°C for 5 hours. After drying, the moisture content should be less than 2% to obtain dried polyphenylene sulfide particles. Step (2): Add the dried polyphenylene sulfide particles with a mass ratio of 100:20:10, styrene-ethylene-butene-styrene block copolymer, and trioctyl acetyl citrate to a high-speed mixer and mix evenly to obtain mixture I; Step (3): Mixture I is introduced into a mixed gas, which is argon and oxygen in a mass ratio of 6:1 and the gas flow rate is 50 sccm. After the mixed gas is introduced, plasma is generated under the action of high-frequency electromagnetic oscillation. The radio frequency power of the high-frequency electromagnetic oscillation is 120W, the electrode spacing is 20 mm, and the time is 6min. After nitrogen is introduced again, the pressure is restored to normal and sealed in a dry environment to obtain mixture II. Step (4): Mixture II is extruded and granulated in stages by a twin-screw extruder under controlled temperature. During granulation, the temperature of the feed section of the twin screw is 170℃, the temperature of the melting section is 310℃, the temperature of the homogenization section is 300℃, the initial screw speed is 50 r / min, the speed during production is 300 r / min, the back pressure is 22 MPa, and the die head pressure is 80 MPa. After extrusion and granulation, modified polyphenylene sulfide is obtained.

[0020] Preparation Example 3 The preparation of modified polyphenylene sulfide includes the following steps: Step (1): Dry the polyphenylene sulfide particles at a temperature of 120°C for 4 hours. After drying, the moisture content should be less than 2% to obtain dried polyphenylene sulfide particles. Step (2): Add the dried polyphenylene sulfide particles with a mass ratio of 90:20:7, styrene-ethylene-butene-styrene block copolymer, and trioctyl acetyl citrate to a high-speed mixer and mix evenly to obtain mixture I; Step (3): Mixture I is introduced into a mixed gas, which is argon and oxygen in a mass ratio of 5:1 and the gas flow rate is 40 sccm. After the mixed gas is introduced, plasma is generated under the action of high-frequency electromagnetic oscillation. The radio frequency power of the high-frequency electromagnetic oscillation is 110W, the electrode spacing is 15 mm, and the time is 5min. After nitrogen is introduced again, the pressure is restored to normal and sealed in a dry environment to obtain mixture II. Step (4): Mixture II is extruded and granulated in stages by a twin-screw extruder under controlled temperature. During granulation, the temperature of the feed section of the twin-screw is 160℃, the temperature of the melting section is 300℃, the temperature of the homogenization section is 290℃, the initial screw speed is 45 r / min, the speed during production is 250 r / min, the back pressure is 20 MPa, and the die head pressure is 70 MPa. After extrusion and granulation, modified polyphenylene sulfide is obtained.

[0021] Example 1 A flame-retardant cable material for a new energy charging pile comprises the following raw materials in parts by weight: 80 parts of low-smoke halogen-free irradiated cross-linked polyolefin, 30 parts of modified polyphenylene sulfide prepared in Preparation Example 1, 20 parts of dioctyl phthalate (composite plasticizer), 10 parts of layered nano-zirconium phosphate (nano flame retardant), and 5 parts of maleic anhydride-grafted ethylene-octene copolymer (complementary solvent).

[0022] The low-smoke halogen-free irradiated crosslinked polyolefin is composed of 45 parts by weight of linear low-density polyethylene, 5 parts of ethylene-vinyl acetate copolymer, 25 parts of aluminum hydroxide, 10 parts of magnesium hydroxide, 1 part of silicone resin, 1 part of triallyl isocyanurate, 0.5 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1 part of zinc stearate, and 1 part of zinc molybdate.

[0023] The preparation method of the above flame-retardant cable material includes the following steps: mixing low-smoke halogen-free irradiated cross-linked polyolefin and modified polyphenylene sulfide, sealing and stirring after purging with nitrogen, stirring at 45°C and 200 rpm for 20 minutes, adding a solvent, purging with nitrogen again and sealing, heating to 55°C, increasing the speed to 400 rpm, and stirring for 20 minutes to obtain a mixture; adding a composite plasticizer and a nano flame retardant to the mixture, heating to 65°C, stirring evenly at 400 rpm, extruding and molding, cooling and granulating to obtain the cable material for new energy charging piles.

[0024] Example 2 A flame-retardant cable material for a new energy charging pile comprises the following raw materials in parts by weight: 100 parts of low-smoke halogen-free irradiated cross-linked polyolefin, 40 parts of modified polyphenylene sulfide prepared in Preparation Example 2, 25 parts of trioctyl acetyl citrate (composite plasticizer), 15 parts of carbon nanotubes (nano flame retardant), and 10 parts of maleic anhydride-grafted ethylene-octene copolymer (complementary solvent).

[0025] The low-smoke halogen-free irradiated crosslinked polyolefin is composed of 55 parts by weight of linear low-density polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 30 parts of aluminum hydroxide, 15 parts of magnesium hydroxide, 3 parts of silicone resin, 2 parts of triallyl isocyanurate, 1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2 parts of zinc stearate, and 3 parts of zinc molybdate.

[0026] The preparation method of the above flame-retardant cable material includes the following steps: mixing low-smoke halogen-free irradiated cross-linked polyolefin and modified polyphenylene sulfide, sealing and stirring after purging with nitrogen, stirring at 55°C and 300 rpm for 25 minutes, adding a solvent, purging with nitrogen again and sealing, heating to 60°C, increasing the speed to 500 rpm, and stirring for 25 minutes to obtain a mixture; adding a composite plasticizer and a nano flame retardant to the mixture, heating to 75°C, stirring evenly at 500 rpm, extruding and molding, cooling and granulating to obtain cable material for new energy charging piles.

[0027] Example 3 A flame-retardant cable material for a new energy charging pile comprises the following raw materials in parts by weight: 90 parts of low-smoke halogen-free irradiated cross-linked polyolefin, 35 parts of modified polyphenylene sulfide prepared in Preparation Example 3, 25 parts of tributyl acetylacetic acid (composite plasticizer), 15 parts of nano magnesium hydroxide (nano flame retardant), and 8 parts of maleic anhydride grafted ethylene-octene copolymer (complementary solvent).

[0028] The low-smoke halogen-free irradiated cross-linked polyolefin is composed of 50 parts by weight of linear low-density polyethylene, 7 parts of ethylene-vinyl acetate copolymer, 30 parts of aluminum hydroxide, 12 parts of magnesium hydroxide, 2 parts of silicone resin, 2 parts of triallyl isocyanurate, 1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1.5 parts of zinc stearate, and 2 parts of zinc molybdate.

[0029] The preparation method of the above flame-retardant cable material includes the following steps: mixing low-smoke halogen-free irradiated cross-linked polyolefin and modified polyphenylene sulfide, sealing and stirring after purging with nitrogen, stirring at 50°C and 250 rpm for 25 minutes, adding a solvent, purging with nitrogen again and sealing, heating to 55°C, increasing the speed to 450 rpm, and stirring for 25 minutes to obtain a mixture; adding a composite plasticizer and a nano flame retardant to the mixture, heating to 70°C, stirring evenly at 450 rpm, extruding and molding, cooling and granulating to obtain the cable material for new energy charging piles.

[0030] Comparative Example The difference between Comparative Example 1 and Example 3 is that the modified polyphenylene sulfide was replaced with commercially available polyphenylene sulfide, which was purchased from Dongguan Yirong Plastic Raw Materials Co., Ltd., with processing grades of injection molding and extrusion, a hardness of 70HB, and a grade of Class 1.

[0031] Comparative Example 1: A flame-retardant cable material for a new energy charging pile, comprising the following raw materials in parts by weight: 90 parts of low-smoke halogen-free irradiated cross-linked polyolefin, 35 parts of commercially available polyphenylene sulfide prepared in Preparation Example 3, 25 parts of acetylsicitious tributyl citrate as the composite plasticizer, 15 parts of nano-magnesium hydroxide as the nano flame retardant, and 8 parts of maleic anhydride-grafted ethylene-octene copolymer as the compatibilizer.

[0032] The low-smoke halogen-free irradiated cross-linked polyolefin is composed of 50 parts by weight of linear low-density polyethylene, 7 parts of ethylene-vinyl acetate copolymer, 30 parts of aluminum hydroxide, 12 parts of magnesium hydroxide, 2 parts of silicone resin, 2 parts of triallyl isocyanurate, 1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1.5 parts of zinc stearate, and 2 parts of zinc molybdate.

[0033] Commercially available comparison The flame-retardant cable material for commercially available charging piles was sourced from Dongguan Puris Plastic Raw Materials Co., Ltd. The material has a specific gravity of 1.10~1.25 g / cm³, molding shrinkage of 1.2%, elongation at break of 550%, embrittlement temperature of -62℃, tensile strength of 15MPa, flame retardancy of UL94 V0, tear strength of 85, glass transition temperature of 100.6~106.1℃, and hardness of 60A-90D.

[0034] Experiment 1 The cable materials obtained in the examples and comparative examples were plasticized and sheeted on an open plasticizer at a plasticizing temperature of 150°C. They were preheated in a hydraulic press for 15 min, pressurized to 15 MPa for 5 min, then pressurized and cooled to room temperature, and allowed to stand for 5 h to obtain the cable material. To evaluate the flame retardancy rating of the material, a vertical burning test and conditions for three flame retardancy ratings were studied. The cable material samples were segmented and their flame retardancy performance was tested using a testing instrument. Type 5 dumbbell-shaped samples, with a thickness of (1 ± 0.1) mm, were prepared by molding. The environmental conditions for cutting the test samples were a temperature of 25°C, a humidity of 45%, and a standing time of 6 h.

[0035] The formula for evaluating flammability rating is as follows:

[0036] In the formula: t f t1 is the flaming time (s) of all samples in each group; t1 + t2 is the flaming time (s) of each sample or the sum of the flaming times after the second test.

[0037] Table 1 Vertical Combustion Performance of Cable Materials in Different Groups

[0038] As shown in Table 1, the cable materials prepared by the methods in Examples 1, 2, and 3 exhibit good flame-retardant effects during vertical combustion, with combustion times all below 50 seconds. Based on the combustion performance of the sample strips, the lower the vertical combustion rating, the better the flame retardant in the cable material, indicating that the cable materials prepared according to the methods in the examples have better flame-retardant effects.

[0039] The tensile strength and oxygen index of different groups of cable materials were measured and statistically analyzed (see Table 2). Tensile strength was measured according to GB / T 2951.11-2008, and the limiting oxygen index was measured according to GB / T 2406.2-2009A. The limiting oxygen index is the minimum volume percentage of oxygen required to sustain combustion of the cable polymer material after ignition in an oxygen-nitrogen mixture. The concentration of the cable samples was measured using an oxygen indexing instrument at an ambient temperature of 25℃ and a humidity of 45%. Each group of samples was tested three times, and the average value was taken.

[0040] The formula for calculating the limiting oxygen index is:

[0041] Table 2 shows that the cable materials prepared by the methods of Examples 1, 2, and 3 exhibit good tensile strength, and their limiting oxygen index is higher than that of the comparative example and the commercially available control. This indicates that by changing the raw materials of the comparative example and replacing the modified polyphenylene sulfide with commercially available polyphenylene sulfide, both the tensile strength and limiting oxygen index of the cable material decreased.

[0042] Table 2. Statistics on tensile strength and oxygen index of cable materials in different groups.

[0043] Conclusion: The flame-retardant cable material for new energy charging piles of this invention features a synergistic effect of various components, resulting in enhanced thermal stability, good flame retardancy, and good tensile strength. It meets the daily usage requirements of cables for new energy charging piles and has application value. In the comparative example, replacing the modified polyphenylene sulfide with commercially available polyphenylene sulfide resulted in a decrease in flame retardancy and tensile strength. Therefore, the addition of modified polyphenylene sulfide to the raw materials enhances the thermal stability and flame retardancy of the cable material.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flame-retardant cable material for new energy charging piles, characterized in that, The raw materials include the following parts by weight: 80-100 parts of low-smoke halogen-free irradiated crosslinked polyolefin, 30-40 parts of modified polyphenylene sulfide, 20-25 parts of composite plasticizer, 10-15 parts of nano flame retardant, and 5-10 parts of compatibilizer. The low-smoke halogen-free irradiated crosslinked polyolefin is composed of the following raw materials in parts by weight: 45-55 parts linear low-density polyethylene, 5-10 parts ethylene-vinyl acetate copolymer, 25-30 parts aluminum hydroxide, 10-15 parts magnesium hydroxide, 1-3 parts silicone resin, 1-2 parts triallyl isocyanurate, 0.5-1 part pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1-2 parts zinc stearate, and 1-3 parts zinc molybdate. The preparation of the modified polyphenylene sulfide includes the following steps: S1: Dry the polyphenylene sulfide particles to reduce their moisture content to less than 3% to obtain dried polyphenylene sulfide particles. S2: Add the dried polyphenylene sulfide particles, styrene-ethylene-butene-styrene block copolymer and trioctyl acetyl citrate to a high-speed mixer and mix evenly to obtain mixture I; S3: Mixture I is introduced into a mixed gas. Under the action of high-frequency electromagnetic oscillation, plasma is generated. Nitrogen gas is introduced to restore normal pressure. The mixture is then sealed in a dry environment to obtain mixture II. S4: Mixture II is extruded and granulated in stages using a twin-screw extruder under controlled temperature to obtain modified polyphenylene sulfide; In step S1, the drying temperature is 120-125℃ and the drying time is 3-5 hours; In step S2, the mass ratio of the dried polyphenylene sulfide particles to the styrene-ethylene-butene-styrene block copolymer and trioctyl acetyl citrate is 80-100:15-20:5-10. In step S3, the mixed gas is argon and oxygen with a mass ratio of 4-6:1, and the gas flow rate is 20-50 sccm; In step S3, the radio frequency power of the high-frequency electromagnetic oscillation is 100-120W, the electrode spacing is 10-20 mm, and the time is 3-6 min.

2. The flame-retardant cable material for a new energy charging pile according to claim 1, characterized in that, In step S4, the temperature of the feeding section is 150-170℃, the temperature of the melting section is 290-310℃, the temperature of the homogenization section is 280-300℃, the initial screw speed is 40-50 r / min, the speed during production is 250-300 r / min, the back pressure is 18-22 MPa, and the die head pressure is 60-80 MPa.

3. The flame-retardant cable material for a new energy charging pile according to claim 1, characterized in that, The nano flame retardant includes at least one of layered nano zirconium phosphate, carbon nanotubes, nano magnesium hydroxide, and nano aluminum hydroxide.

4. The flame-retardant cable material for a new energy charging pile according to claim 1, characterized in that, The composite plasticizer includes at least one of dioctyl phthalate, trioctyl acetyl citrate, and tributyl acetyl citrate; the solvent is maleic anhydride-grafted ethylene-octene copolymer.

5. The flame-retardant cable material for a new energy charging pile according to claim 1, characterized in that, The preparation steps of flame-retardant cable material include: mixing low-smoke halogen-free irradiated cross-linked polyolefin and modified polyphenylene sulfide, sealing and stirring after purging with nitrogen, stirring at a temperature of 45-55℃ and a speed of 200-300 rpm for 20-25 minutes, adding a solvent, purging with nitrogen again and sealing, raising the temperature to 55-60℃, increasing the speed to 400-500 rpm, and stirring for 20-25 minutes to obtain a mixture; adding a composite plasticizer and a nano flame retardant to the mixture, raising the temperature to 65-75℃, stirring evenly at a speed of 400-500 rpm, extruding and molding, cooling and granulating to obtain cable material for new energy charging piles.

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