Electrical wire and cable high speed extrusion molding medium, method and process

Abstract

The present application relates to a kind of electric wire cable high-speed extrusion forming medium, method and process, belong to cable preparation technical field, to solve the instability of melt rheological behavior in high-speed extrusion process, easy to produce surface defect and medium uniformity control problem, the present application is by optimizing medium formula, introduce polyvinyl chloride resin, heat stabilizer, plasticizer, nano composite filler, functional additive etc., and be combined with conductor pretreatment, nano filler surface treatment, gradient temperature control extrusion, ultrasonic vibration auxiliary, on-line dielectric monitoring and feedback regulation and control and gradient cooling etc. Integrated process, realizes the synchronous promotion of processing dynamic stability and product comprehensive performance, effectively avoids melt rupture, guarantees insulation layer density and consistency, significantly improves production efficiency and reduces energy consumption, provides reliable technical path for the large-scale manufacturing of high-performance electric wire cable.

Description

Technical Field

[0001] This invention belongs to the field of cable manufacturing technology, specifically referring to a high-speed extrusion molding medium, method, and process for wires and cables. Background Technology

[0002] Electric wires and cables are the core carriers of power transmission and information communication. The level of manufacturing technology is related to the reliability and efficiency of energy and communication networks. Among them, the extrusion molding process is the key link that determines the quality of cable insulation and sheath. At present, with the upgrading of power system and the rapid development of information infrastructure, the market has put forward higher requirements for the production efficiency, structural consistency and long-term operational stability of electric wires and cables. This has prompted extrusion technology to continuously develop towards high speed and precision. The industry has accumulated a lot of practical experience in extrusion medium formulation, screw structure design, temperature and pressure control strategies and online testing. The aim is to optimize the rheological properties, melt uniformity and cooling molding effect in the extrusion process to adapt to the processing characteristics of different insulation and sheath materials, and improve the overall output capacity of the production line and the uniformity of product performance.

[0003] The current challenges in this field lie in the fact that, with the significant increase in extrusion speed, the melt rheological behavior during processing is difficult to control stably, which can easily lead to melt fracture and surface defects. At the same time, the uniformity of the medium and the density of the insulation layer are also challenged. In addition, under high shear rates, how to balance melt strength and flowability, achieve efficient dispersion of fillers and enhance interfacial bonding strength, and establish an effective online monitoring and real-time control mechanism to ensure the long-term electrical insulation reliability of products are all key technical bottlenecks that restrict the further improvement of production efficiency and overall performance. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a high-speed extrusion molding medium, method and process for wires and cables, which effectively solves the problem that it is difficult to balance production efficiency, product surface quality and medium uniformity in the current wire and cable extrusion process.

[0005] The technical solution adopted in this invention is as follows: This invention proposes a high-speed extrusion molding medium, method, and process for electric wires and cables, comprising the following raw materials in parts by weight:

[0006] 100 parts polyvinyl chloride resin; 4.5-5.5 parts composite calcium-zinc heat stabilizer; 22-28 parts trioctyl trimellitate; 8-12 parts nano-calcined kaolin with surface-grafted silane coupling agent; 3-6 parts hydrogenated styrene-butadiene block copolymer; 1.5-2.5 parts zirconium oxide nanofibers; 14-18 parts composite flame retardant; 1.2-2.0 parts dielectric loss modifier.

[0007] Furthermore, the composite flame retardant is a compound system of aluminum hypophosphite and melamine cyanurate, with a mass ratio of 1:(0.8-1.2).

[0008] Furthermore, the silane coupling agent grafted onto the surface of the nano-calcined kaolin is KH-570; the aspect ratio of the zirconium oxide nanofibers is greater than 50.

[0009] Furthermore, it includes the following steps:

[0010] S1. Perform plasma cleaning on the conductor and coat it with a silane coupling agent transition layer;

[0011] S2. Perform fluidized bed dry surface treatment on the nanofiller;

[0012] S3. The components of the medium are mixed at high speed and granulated by two-stage extrusion to prepare cable material;

[0013] S4. The cable material is passed through an extruder with a gradient temperature control system and, with the assistance of an ultrasonic vibration die, is wrapped around the pretreated conductor to form an insulation layer.

[0014] S5. Perform gradient cooling and online detection and cutting on the wrapped cable.

[0015] Further, in step S1, the plasma cleaning power is 2kW; in step S2, the fluidized bed treatment temperature is 110℃, the treatment time is 25 minutes, and the silane coupling agent used is 0.8% of the powder weight.

[0016] Further, in step S4, the temperature settings of the gradient temperature control system along the extruder barrel to the die head are sequentially: 155℃, 168℃, 172℃, 165℃, and 160℃; the vibration frequency of the ultrasonic vibration die head is 28kHz, and the amplitude is 5μm.

[0017] Furthermore, the process includes online rheological-dielectric synergistic regulation, specifically:

[0018] An online dielectric spectrometer is installed in front of the extrusion die to monitor the dielectric constant of the melt in real time.

[0019] A feedback control system is established so that when the monitored dielectric constant fluctuation exceeds the set threshold ±0.05, the temperature of the third zone (dynamic crosslinking zone) of the extruder is automatically adjusted to achieve dynamic balance of the melt state.

[0020] 8. Further, the gradient cooling process comprises three stages performed sequentially:

[0021] The first stage is atomized water cooling, with the water temperature controlled at 40℃;

[0022] The second stage is vortex air cooling, with a wind speed of 8 m / s;

[0023] The third stage involves infrared equilibrium heat treatment.

[0024] Furthermore, the screw speed in the extrusion process is 380-450 rpm, the corresponding extrusion speed is 1200-1500 m / min, and the melt pressure is maintained at 18-22 MPa.

[0025] Furthermore, the online inspection uses a synchronous scanning X-ray detector to check the uniformity of the insulation layer, and automatically cuts the finished cable into different grades based on the comprehensive online and offline test results of the dielectric properties.

[0026] The beneficial effects achieved by the present invention using the above solution are as follows:

[0027] This solution proposes a high-speed extrusion molding medium, method, and process for wires and cables. By deeply integrating a gradient functionalized medium system with online rheology-dielectric synergistic control technology, it achieves simultaneous improvement in processing stability and the overall performance of the final product during high-speed extrusion. At the material level, it introduces nanocomposite fillers with shear-responsive characteristics and molecularly coupled functional additives to effectively coordinate melt strength and flow properties in the die relaxation zone under high shear rates. This significantly increases extrusion speed while avoiding melt fracture and surface defects. At the process level, it innovatively combines online dielectric monitoring with an adaptive temperature control system to achieve real-time feedback and dynamic precise control of medium uniformity, ensuring the density and consistency of the insulation layer structure. Furthermore, through conductor pretreatment and ultrasonic-assisted dispersion technology, it strengthens interfacial bonding and filler dispersion, further optimizing the product's strength and long-term electrical insulation reliability. This integrated solution fundamentally resolves the contradiction between high-speed extrusion and material performance, significantly improving production efficiency and reducing unit energy consumption while ensuring excellent electrical insulation performance, providing a reliable technical path for the large-scale manufacturing of high-performance wires and cables. Attached Figure Description

[0028] Figure 1 This is a process flow diagram of a high-speed extrusion molding medium for wires and cables proposed in this invention;

[0029] Figure 2 This is a comparison chart of the performance verification results of a high-speed extrusion molding medium for wires and cables proposed in this invention;

[0030] Figure 3 This is a comparison chart of the performance verification results of a high-speed extrusion molding medium for wires and cables proposed in this invention;

[0031] Figure 4 This is a comparison chart of the performance verification results of a high-speed extrusion molding medium for wires and cables proposed in this invention;

[0032] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that, unless otherwise specified, all chemical reagents involved in this invention were purchased through commercial channels.

[0035] The polyvinyl chloride resin (SG-5) used in this invention was purchased from Shanghai Chlor-Alkali Chemical Co., Ltd.; the composite calcium-zinc heat stabilizer (CZX-100) was purchased from Shandong Ruifeng Polymer Materials Co., Ltd.; trioctyl trimellitate (industrial grade, 99%) was purchased from Jiangsu Raymond Chemical Technology Co., Ltd.; nano-calcined kaolin (nanoscale, particle size 50nm) with surface-grafted silane coupling agent was purchased from Hunan Aihua Group Co., Ltd.; hydrogenated styrene-butadiene block copolymer (SEBS, G1651) was purchased from Kraton Polymers, Inc.; zirconium oxide nanofibers (nanoscale, diameter 100nm) were purchased from Beijing Nachen Technology Co., Ltd.; the composite flame retardant (FR-202) was purchased from Jiangsu Yake Technology Co., Ltd.; and the dielectric loss regulator (DMA-100) was purchased from Shenzhen Xinzhoubang Technology Co., Ltd.

[0036] Example 1

[0037] A method and process for high-speed extrusion molding of wires and cables

[0038] The high-speed extrusion molding medium for wires and cables prepared in this scheme includes the following steps:

[0039] First, the copper conductor with a diameter of 0.5 mm is pretreated and cleaned in an argon plasma device with a power of 2 kW. Then, a silane coupling agent film with a thickness of about 0.5 μm is formed on its surface by dip coating to enhance the interfacial bonding. The preparation process of the dielectric material is as follows: 100 parts by weight of polyvinyl chloride resin with a degree of polymerization of 1300, 22 parts by weight of trioctyl trimellitate as the main plasticizer, and 7 parts by weight of epoxidized soybean oil as the auxiliary plasticizer are put into a high-speed mixer, mixed at a speed of 500 rpm and heated to 80°C.

[0040] Subsequently, 4.5 parts by weight of a composite calcium-zinc heat stabilizer containing rare earth elements, 8 parts by weight of nano-calcined kaolin dry-surface treated with KH-570 silane coupling agent, 3 parts by weight of hydrogenated styrene-butadiene block copolymer, 1.5 parts by weight of zirconium oxide nanofibers with an aspect ratio greater than 50, a composite flame retardant composed of 7 parts by weight of aluminum hypophosphite and 7 parts by weight of melamine cyanurate, 0.8 parts by weight of antioxidant 1010 / 168 compound, 0.5 parts by weight of calcium stearate, 2 parts by weight of rutile titanium dioxide coated with alumina, and 1.2 parts by weight of polyaryletherketone micro powder were added sequentially.

[0041] After continuing to mix and heat to 115°C, the material is transferred to a cooling mixer and stirred to cool down to below 45°C. The resulting mixture is then melt-mixed, sheared, and granulated by a two-stage granulation system consisting of a co-rotating parallel twin-screw extruder and a single-screw extruder. The temperature of each zone of the twin-screw is set at 150-170°C, and the die head temperature of the single-screw is 165°C. Hot cutting granulation is performed using the die surface, and the granules are cooled and dried with 60°C circulating water before use.

[0042] The aforementioned special granules were fed into a single-screw extruder with an L / D ratio of 30:1. The temperatures of the five temperature zones from the feed section to the die were set to 155℃, 168℃, 172℃, 165℃, and 160℃, respectively. The pretreated copper conductor was coated under the conditions of a screw speed of 380 rpm and a melt pressure of 18 MPa. The extrusion die was equipped with an ultrasonic vibration device with a frequency of 28 kHz and an amplitude of 5 μm.

[0043] An online dielectric spectrometer is installed in front of the mold head to monitor the dielectric constant of the melt in real time. The temperature of the third zone (172℃) is dynamically fine-tuned through a closed-loop control system to keep the dielectric constant fluctuation within ±0.05. The wrapped cable immediately enters a three-stage gradient cooling system: the first stage is atomized water cooling at 40℃ with a cooling length of 2m; the second stage is vortex air cooling with a wind speed of 8m / s and a cooling length of 3m; the third stage is an infrared balance heat treatment zone with a power density of 3W / cm².

[0044] Finally, the finished products are subjected to non-destructive testing by a synchronous scanning X-ray detector, and are automatically cut according to the online dielectric properties and appearance inspection results to obtain finished cables with an extrusion line speed of 1200m / min.

[0045] Example 2

[0046] A method and process for high-speed extrusion molding of wires and cables

[0047] The high-speed extrusion molding medium for wires and cables prepared in this scheme includes the following steps:

[0048] First, the copper conductor with a diameter of 0.8 mm is pretreated and cleaned in an argon plasma device with a power of 2 kW. Then, a silane coupling agent film with a thickness of about 0.8 μm is formed on its surface by dip coating to enhance the interfacial bonding. The preparation process of the dielectric material is as follows: 100 parts by weight of polyvinyl chloride resin with a degree of polymerization of 1300, 25 parts by weight of trioctyl trimellitate as the main plasticizer, and 8 parts by weight of epoxidized soybean oil as the auxiliary plasticizer are put into a high-speed mixer, mixed at a speed of 500 rpm and heated to 80°C.

[0049] Subsequently, 5.0 parts by weight of a composite calcium-zinc heat stabilizer containing rare earth elements, 10 parts by weight of nano-calcined kaolin dry-surface treated with KH-570 silane coupling agent, 4.5 parts by weight of hydrogenated styrene-butadiene block copolymer, 2.0 parts by weight of zirconium oxide nanofibers with an aspect ratio greater than 50, a composite flame retardant composed of 8 parts by weight of aluminum hypophosphite and 8 parts by weight of melamine cyanurate, 1.0 parts by weight of antioxidant 1010 / 168 compound, 0.75 parts by weight of calcium stearate, 3 parts by weight of rutile titanium dioxide coated with alumina, and 1.6 parts by weight of polyaryletherketone micro powder were added sequentially.

[0050] After continuing to mix and heat to 115°C, the material is transferred to a cooling mixer and stirred to cool down to below 45°C. The resulting mixture is then melt-mixed, sheared, and granulated by a two-stage granulation system consisting of a co-rotating parallel twin-screw extruder and a single-screw extruder. The temperature of each zone of the twin-screw is set at 150-170°C, and the die head temperature of the single-screw is 165°C. Hot cutting granulation is performed using the die surface, and the granules are cooled and dried with 60°C circulating water before use.

[0051] The above-mentioned special granules were fed into a single-screw extruder with an L / D ratio of 30:1. The temperatures of the five temperature zones from the feed section to the die were set to 155℃, 168℃, 172℃, 165℃ and 160℃, respectively. The pretreated copper conductor was coated under the conditions of a screw speed of 415 rpm and a melt pressure of 20 MPa.

[0052] The extrusion die is equipped with an ultrasonic vibration device with a frequency of 28kHz and an amplitude of 5μm.

[0053] An online dielectric spectrometer is installed in front of the mold head to monitor the dielectric constant of the melt in real time. The temperature of the third zone (172℃) is dynamically fine-tuned through a closed-loop control system to keep the dielectric constant fluctuation within ±0.05. The wrapped cable immediately enters a three-stage gradient cooling system: the first stage is atomized water cooling at 40℃ with a cooling length of 2m; the second stage is vortex air cooling with a wind speed of 8m / s and a cooling length of 3m; the third stage is an infrared balance heat treatment zone with a power density of 3W / cm².

[0054] Finally, the finished products are subjected to non-destructive testing by a synchronous scanning X-ray detector, and are automatically cut according to the online dielectric properties and appearance inspection results to obtain finished cables with an extrusion line speed of 1350m / min.

[0055] Example 3

[0056] A method and process for high-speed extrusion molding of wires and cables

[0057] The high-speed extrusion molding medium for wires and cables prepared in this scheme includes the following steps:

[0058] First, a copper conductor with a diameter of 1.0 mm is pretreated and cleaned in an argon plasma device with a power of 2 kW. Then, a silane coupling agent film with a thickness of about 1.0 μm is formed on its surface by dip coating to enhance the interfacial bonding. The preparation process of the dielectric material is as follows: 100 parts by weight of polyvinyl chloride resin with a degree of polymerization of 1300, 28 parts by weight of trioctyl trimellitate as the main plasticizer, and 9 parts by weight of epoxidized soybean oil as the auxiliary plasticizer are put into a high-speed mixer, mixed at a speed of 500 rpm and heated to 80°C.

[0059] Subsequently, 5.5 parts by weight of a composite calcium-zinc heat stabilizer containing rare earth elements, 12 parts by weight of nano-calcined kaolin dry-surface treated with KH-570 silane coupling agent, 6 parts by weight of hydrogenated styrene-butadiene block copolymer, 2.5 parts by weight of zirconium oxide nanofibers with an aspect ratio greater than 50, a composite flame retardant composed of 9 parts by weight of aluminum hypophosphite and 9 parts by weight of melamine cyanurate, 1.2 parts by weight of antioxidant 1010 / 168 compound, 1.0 parts by weight of calcium stearate, 4 parts by weight of rutile titanium dioxide coated with alumina, and 2.0 parts by weight of polyaryletherketone micro powder were added sequentially.

[0060] After continuing to mix and heat to 115°C, the material is transferred to a cooling mixer and stirred to cool down to below 45°C. The resulting mixture is then melt-mixed, sheared, and granulated by a two-stage granulation system consisting of a co-rotating parallel twin-screw extruder and a single-screw extruder. The temperature of each zone of the twin-screw is set at 150-170°C, and the die head temperature of the single-screw is 165°C. Hot cutting granulation is performed using the die surface, and the granules are cooled and dried with 60°C circulating water before use.

[0061] The above-mentioned special granules were fed into a single-screw extruder with an L / D ratio of 30:1. The temperatures of the five temperature zones from the feed section to the die were set to 155℃, 168℃, 172℃, 165℃ and 160℃, respectively. The pretreated copper conductor was coated under the conditions of a screw speed of 450 rpm and a melt pressure of 22 MPa.

[0062] The extrusion die is equipped with an ultrasonic vibration device with a frequency of 28kHz and an amplitude of 5μm.

[0063] An online dielectric spectrometer is installed in front of the mold head to monitor the dielectric constant of the melt in real time. The temperature of the third zone (172℃) is dynamically fine-tuned through a closed-loop control system to keep the dielectric constant fluctuation within ±0.05. The wrapped cable immediately enters a three-stage gradient cooling system: the first stage is atomized water cooling at 40℃ with a cooling length of 2m; the second stage is vortex air cooling with a wind speed of 8m / s and a cooling length of 3m; the third stage is an infrared balance heat treatment zone with a power density of 3W / cm².

[0064] Finally, the finished products are subjected to non-destructive testing by a synchronous scanning X-ray detector, and are automatically cut according to the online dielectric properties and appearance inspection results to obtain finished cables with an extrusion line speed of 1500m / min.

[0065] Comparative Example 1

[0066] An extrusion molding medium for wires and cables and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the medium formulation does not contain hydrogenated styrene-butadiene block copolymer and polyaryletherketone micro powder.

[0067] Experimental Example 1

[0068] The experiment begins with sample preparation, such as... Figure 1 The process flow shown is as follows: the first stage is conductor pretreatment, in which three rolls of copper conductors with the same specifications and a diameter of 0.8 mm are taken and cleaned in an argon plasma device with a power of 2 kW. Then, a silane coupling agent transition layer with a thickness of about 0.8 μm is immediately formed on the surface of the conductor by dip coating. After completion, it is marked for later use. The second stage is the preparation of cable material, which must be carried out strictly according to the grouping.

[0069] For the experimental group (Group A) and the process control group (Group C), the formulation of Example 2 was strictly followed: PVC resin, trioctyl trimellitate (TOTM), and epoxidized soybean oil were added to a high-speed mixer, mixed at 500 rpm, and heated to 80°C; then, composite calcium-zinc stabilizer, KH-570-treated nano-calcined kaolin, hydrogenated styrene-butadiene block copolymer (SEBS), zirconium oxide nanofibers, flame retardant (composed of aluminum hypophosphite and melamine cyanurate in a 1:1 mass ratio), antioxidant, calcium stearate, and titanium dioxide were added sequentially. The mixture was prepared by mixing and heating the powder and polyaryletherketone (PAEK) micro powder. After heating to 115°C, the mixture was transferred to a cooling mixer and stirred to cool down to below 45°C. Finally, the material was melt-mixed and hot-cut into granules by a two-stage extrusion granulation system (twin screw temperature 150-170°C, single screw die head 165°C). The granules were cooled and dried by circulating water at 60°C and then sealed and marked as raw material of group A / C. For the control group (group B), the preparation process was exactly the same as above, except that SEBS and PAEK micro powder were not added to the formula. The resulting granules were marked as raw material of group B.

[0070] After completing the raw material preparation, the third stage involves cable extrusion molding. Three experimental groups were conducted in parallel using different process combinations. The experimental group (Group A) followed the full protocol: Group A granules were fed into a single-screw extruder, with five temperature stages from the feed section to the die set at 155℃, 168℃, 172℃, 165℃, and 160℃ respectively. Simultaneously, an ultrasonic vibration die (28kHz, 5μm) and an online dielectric spectrometer and feedback control system (with a dielectric constant fluctuation threshold set to ±0.05) were activated. The pre-treated conductor was coated under conditions of a screw speed of 415rpm and a melt pressure of approximately 20MPa. The coated cable immediately entered a three-stage gradient cooling system (40℃ mist cooling). The first group underwent water cooling, 8 m / s eddy current air cooling, and 3 W / cm² infrared equilibrium heat treatment. Finally, the samples were inspected by a synchronous scanning X-ray detector and then cut and collected as qualified products. The control group (Group B) used Group B granules, but all process settings, including the advanced online control and cooling system, were completely consistent with Group A to examine the impact of formulation differences. The process comparison group (Group C) used the complete formulation granules of Group A, but the key processes were turned off: the ultrasonic vibration head was turned off, the online dielectric monitoring and feedback system was turned off (the temperature of the third zone was fixed at 172℃), and traditional single-stage water cooling was used instead of gradient cooling. The remaining process parameters were the same as those of Group A. This was done to evaluate the independent contribution of the innovative process.

[0071] After sample preparation, the second stage of performance testing and characterization will begin. Samples from the three groups of finished cables will be taken for a series of parallel tests, with at least five samples taken from each group to calculate the average value. The tests include: processing performance (such as observing melt fracture phenomena and measuring extrusion swell ratio using a high-speed camera), finished product physical properties (such as tensile strength, elongation at break, and retention rate after thermal aging), insulation quality and electrical properties (such as using X-rays to detect insulation uniformity, testing dielectric constant, loss tangent, and breakdown field strength), flame retardant properties (such as oxygen index and vertical flammability rating), and observation of the microstructure of the insulation cross-section using a scanning electron microscope (SEM) to comprehensively and quantitatively evaluate the advantages and disadvantages of different schemes.

[0072] Experimental results are as follows Figure 2 , Figure 3 , Figure 4 As shown, the solution employing the process described in the example significantly improves melt stability during high-speed extrusion, effectively preventing surface defects and resulting in a smooth and uniform insulation layer. This solution also significantly enhances the toughness, heat aging resistance, and insulation density of the finished cable, ensuring reliable electrical insulation strength and superior, stable dielectric properties. In contrast, formulations lacking key components exhibit significant processing difficulties and performance degradation even under the same process, while solutions lacking advanced process assistance struggle to fully realize the potential of high-quality formulations. The results demonstrate that this integrated technology solution, through deep synergy between the material system and processing technology, successfully achieves precise control and comprehensive improvement of product performance at extremely high production efficiency, fully proving its technological advancement and engineering application value.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0075] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A high-speed extrusion molding medium for wires and cables, characterized in that: The ingredients include the following parts by weight: 100 parts polyvinyl chloride resin; 4.5-5.5 parts composite calcium-zinc heat stabilizer; 22-28 parts trioctyl trimellitate; 8-12 parts nano-calcined kaolin with surface-grafted silane coupling agent; 3-6 parts hydrogenated styrene-butadiene block copolymer; 1.5-2.5 parts zirconium oxide nanofibers; 14-18 parts composite flame retardant; 1.2-2.0 parts dielectric loss modifier.

2. The high-speed extrusion molding medium for wires and cables according to claim 1, characterized in that: The composite flame retardant is a compound system of aluminum hypophosphite and melamine cyanurate, with a mass ratio of 1:(0.8-1.2).

3. The high-speed extrusion molding medium for wires and cables according to claim 2, characterized in that: The silane coupling agent grafted onto the surface of the nano-calcined kaolin is KH-570; the aspect ratio of the zirconium oxide nanofibers is greater than 50.

4. The high-speed extrusion molding method for wires and cables according to claim 3, characterized in that: Includes the following steps: S1. Perform plasma cleaning on the conductor and coat it with a silane coupling agent transition layer; S2. Perform fluidized bed dry surface treatment on the nanofiller; S3. The components of the medium are mixed at high speed and granulated by two-stage extrusion to prepare cable material; S4. The cable material is passed through an extruder with a gradient temperature control system and, with the assistance of an ultrasonic vibration die, is wrapped around the pretreated conductor to form an insulation layer. S5. Perform gradient cooling and online detection and cutting on the wrapped cable.

5. The high-speed extrusion molding method for wires and cables according to claim 4, characterized in that: In step S1, the plasma cleaning power is 2kW; in step S2, the fluidized bed treatment temperature is 110℃, the treatment time is 25 minutes, and the silane coupling agent used is 0.8% of the powder weight.

6. The high-speed extrusion molding method for wires and cables according to claim 5, characterized in that: In step S4, the temperature settings of the gradient temperature control system along the extruder barrel to the die head are as follows: 155℃, 168℃, 172℃, 165℃, and 160℃; the vibration frequency of the ultrasonic vibration die head is 28kHz and the amplitude is 5μm.

7. A high-speed extrusion molding process for wires and cables according to any one of claims 4-6, characterized in that: This process includes online rheological-dielectric coordinated control, specifically: An online dielectric spectrometer is installed in front of the extrusion die to monitor the dielectric constant of the melt in real time. A feedback control system is established so that when the monitored dielectric constant fluctuation exceeds the set threshold ±0.05, the temperature of the third zone (dynamic crosslinking zone) of the extruder is automatically adjusted to achieve dynamic balance of the melt state.

8. The high-speed extrusion molding process for wires and cables according to claim 7, characterized in that: The gradient cooling process comprises three stages performed sequentially: The first stage is atomized water cooling, with the water temperature controlled at 40℃; The second stage is vortex air cooling, with a wind speed of 8 m / s; The third stage involves infrared equilibrium heat treatment.

9. The high-speed extrusion molding process for wires and cables according to claim 8, characterized in that: The screw speed in the extrusion process is 380-450 rpm, the corresponding extrusion speed is 1200-1500 m / min, and the melt pressure is maintained at 18-22 MPa.

10. The high-speed extrusion molding process for wires and cables according to claim 9, characterized in that: The online inspection uses a synchronous scanning X-ray detector to check the uniformity of the insulation layer, and automatically cuts the finished cable into different grades based on the comprehensive online and offline test results of dielectric properties.

Images