A UL certified high-temperature-resistant flame-retardant power signal composite cable and a preparation method thereof

Abstract

The application discloses a UL authentication high-temperature-resistant flame-retardant power signal composite cable and a preparation method thereof, and relates to the technical field of composite cables.The cable core assembly and the outer sheath layer extruded outside the cable core assembly are included.The cable core assembly comprises a plurality of power insulation core wires, at least one group of shielded signal line core units, a filler and a total wrapping layer.The plurality of power insulation core wires and the at least one group of shielded signal line core units are arranged along the circumference to form a cable core body, the filler is filled in the internal gap of the cable core body, and the total wrapping layer is wrapped around the outside of the cable core body and the filler.The power insulation core wires and the shielded signal line core units are combined into a cable structure, power supply and shielded signal transmission functions can be integrated in a single cable, the problems of large space occupation, high construction cost and signal susceptibility to electromagnetic interference of traditional split laying cables are solved, and the effects of integrated wiring and high-stability signal transmission are realized.

Description

Technical Field

[0001] This invention relates to the field of composite cable technology, specifically to a UL-certified high-temperature resistant and flame-retardant power signal composite cable and its preparation method. Background Technology

[0002] Power signal composite cable is an integrated cable product that integrates power transmission and low-voltage control signal transmission. This type of product must meet the UL series safety standards set by Underwriters Laboratories in the United States and pass the testing and certification of core items such as electrical insulation temperature resistance and flame retardancy. It is mainly used in the electrical systems of industrial automation equipment and production lines, and is widely applicable to indoor industrial wiring scenarios with safety compliance certification requirements. Currently, most similar cables employ separate installation methods for power and signal lines, resulting in a large overall installation space occupation, high construction costs, and the potential for electromagnetic interference from power lines to signal lines when laid in parallel, affecting signal transmission stability. Furthermore, ordinary PVC cables have limited temperature resistance and flame retardant properties, failing to meet the long-term high-temperature operation and flame retardant safety requirements under the UL certification system. Therefore, this paper proposes a UL-certified high-temperature resistant and flame-retardant composite power and signal cable and its manufacturing method to address these issues. Summary of the Invention

[0003] Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a UL-certified high-temperature resistant and flame-retardant power signal composite cable and its preparation method, thus solving the problems mentioned in the background section.

[0004] Technical solution To achieve the above objectives, the present invention provides the following technical solution: a UL-certified high-temperature resistant and flame-retardant power signal composite cable, comprising a cable core assembly and an outer sheath extruded around the outside of the cable core assembly; the cable core assembly comprises multiple power insulated core wires, at least one set of shielded signal core units, filler, and a total wrapping tape layer; the multiple power insulated core wires and at least one set of shielded signal core units are arranged circumferentially to form the cable core body, the filler fills the internal gaps of the cable core body, and the total wrapping tape layer wraps around and covers the outside of the cable core body and the filler.

[0005] The goal of this overall structural design is to address the shortcomings of existing technologies where separate installation of power supply cables and signal transmission cables results in large installation space requirements, high construction and cabling costs, and electromagnetic interference and poor signal transmission stability caused by parallel installation of power lines. It also addresses the issues of insufficient temperature resistance and poor flame retardancy of ordinary PVC cables, failing to meet the UL certification requirements for long-term operation at 105℃ and VW-1 flame retardancy. With defined structural layers, a single cable can simultaneously achieve power supply, shielded signal transmission, and high-temperature flame retardancy. Furthermore, the various structural layers work together, resulting in overall performance superior to simple combinations of single-function cables, making it suitable for integrated cabling needs in industrial equipment, automated production lines, and other similar scenarios.

[0006] The power insulated core wire is the carrier of power transmission in the cable. Each power insulated core wire consists of a power conductor and a power insulation layer extruded over the outside of the power conductor. The purpose of this component is to undertake the power transmission function of the main circuit, and to achieve electrical isolation between conductors through the extrusion of the insulation layer, thus ensuring power supply safety.

[0007] Preferably, the cross-sectional area of ​​the power conductor is 4.0 mm². 2 This cross-sectional area is a common power specification for UL-certified flexible cables, which can meet the load current requirements of conventional industrial equipment; if the cross-sectional area is too small, the current carrying capacity will be insufficient and it will not be able to meet the power supply requirements; if the cross-sectional area is too large, the overall outer diameter of the cable will be too large, the bending performance of the wiring will be reduced, and the material cost will be significantly increased.

[0008] Preferably, the power insulation layer is a PVC insulation layer, specifically a 105°C flame-retardant PVC material. PVC insulation material has good electrical insulation and mechanical wear resistance, mature processing technology, and controllable cost; the use of a 105°C temperature-resistant formula is suitable for long-term high-temperature working scenarios of cables, avoiding the problem of rapid aging and insulation performance degradation of ordinary 70°C PVC in high-temperature environments; the addition of flame-retardant components to the material can improve the overall flame-retardant safety performance of the cable.

[0009] The shielded signal core unit serves as the transmission carrier for control signals in the cable. From the inside out, the shielded signal core unit comprises a twisted pair, an inner insulating strip, a braided shielding layer, and an outer insulating strip. The purpose of this component is to achieve stable transmission of low-voltage control signals, isolate electromagnetic interference from the power lines through the shielding structure, and protect the internal signal cores through its layered structure, ensuring the integrity and reliability of signal transmission.

[0010] The twisted pair consists of two signal insulated core wires twisted together. Each signal insulated core wire comprises a signal conductor and a signal insulation layer extruded onto the outside of the signal conductor. The purpose of the twisted structure is to cancel electromagnetic coupling interference between the wires through the periodic twisting of the two core wires, reduce crosstalk and external radiation of the signal itself, and improve the stability of differential signal transmission.

[0011] Preferably, the cross-sectional area of ​​the signal conductor is 0.5 mm². 2 This cross-sectional area is a common specification for industrial control signal cables, which can meet the transmission requirements of conventional analog and switching signals. If the cross-sectional area is too small, the DC resistance of the conductor will be too large, resulting in severe signal attenuation. If the cross-sectional area is too large, the signal core will be too stiff, making it more difficult to twist and increasing the overall outer diameter of the cable.

[0012] Preferably, the signal insulation layer is a PVC insulation layer, using the same 105℃-rated flame-retardant PVC material as the power insulation layer. Using the same temperature-resistant material ensures that the temperature resistance of all internal components of the cable is consistent, preventing premature aging and failure of local materials, while also reducing the types of materials and simplifying production control processes.

[0013] Both the inner and outer insulating strips are made of polyester tape and are respectively installed on the inner and outer sides of the braided shielding layer. The purpose of the double-layer insulating strips is that the inner insulating strip can isolate the signal insulation layer from the braided shielding layer, preventing the braided copper wires from piercing the insulation layer and causing insulation defects; the outer insulating strip can fix the structure of the braided shielding layer, preventing the braided wires from loosening and shifting, while also isolating the shielding layer from external fillers and wrapping tapes, improving the structural stability of the cable core. Polyester tape is characterized by its thinness, high strength, and good electrical insulation performance, without increasing the outer diameter of the cable, and can withstand the temperature shock during processing.

[0014] The braided shielding layer is a tin-plated copper wire braided shielding layer with a braiding density of ≥80%. The purpose of setting the braided shielding layer is to form a continuous conductive shielding layer, blocking the interference of alternating electromagnetic fields generated by external power lines on internal signal lines, while suppressing the electromagnetic radiation of the signal itself, thus meeting the electromagnetic compatibility requirements in industrial environments. Using tin-plated copper wire can improve the conductor's oxidation resistance, extend the service life of the shielding structure, and avoid the problem of reduced shielding effectiveness after pure copper wire oxidizes.

[0015] The reason for limiting the braiding density to ≥80% is that when the braiding density is less than 80%, the coverage of the shielding layer is insufficient, the electromagnetic leakage increases, and the shielding attenuation effect in the low-frequency band decreases significantly. If the braiding density is too high, it will greatly increase the amount of material used and processing time, reduce the flexibility of the cable, and the improvement of shielding effectiveness tends to be gradual, thus reducing the cost-effectiveness.

[0016] The filler, made of cotton thread, fills the internal gaps of the cable core body. The purpose of this component is to fill the internal gaps formed after the power and signal cores are twisted together, ensuring the roundness of the cable core cross-section, preventing core deformation and core displacement, and simultaneously buffering external pressure to improve the cable's mechanical resistance to compression. Cotton thread is soft, inexpensive, and has a certain shock-absorbing and cushioning capacity without damaging the core insulation layer; it is a standard filler material used in the cabling process.

[0017] A main wrapping layer, made of non-woven fabric, is wrapped around the outside of the cable core and filler. The purpose of this component is to tighten and secure all internal core wires and filler, preventing them from loosening and shifting after cabling. It also forms an isolation layer between the cable core and the outer sheath, preventing molten metal from seeping into the cable core during sheath extrusion and ensuring uniform sheath thickness. The non-woven fabric is soft, has uniform thickness, and leaves the cable core surface smooth after wrapping, improving the appearance quality of subsequent sheath extrusion. It also offers good electrical insulation performance and cost advantages.

[0018] The outer sheath is extruded onto the outside of the cable core assembly, forming the outermost protective structure of the cable. This outer sheath is made of PVC. The purpose of this component is to provide mechanical, moisture, and chemical corrosion protection for the internal cable core, while also providing flame retardant and fire-resistant protection for the cable's outermost layer. It is one of the core components that ensures the cable meets UL safety certification. The sheath, made with a 105℃ flame-retardant PVC formula, possesses excellent abrasion resistance, oil resistance, and aging resistance, making it suitable for indoor industrial environments. It also ensures the cable meets VW-1 vertical combustion self-extinguishing requirements, complying with UL safety standards.

[0019] Preferably, the cable has a rated operating voltage of 600V and a power frequency withstand voltage of 2000V for 5 minutes without breakdown. This voltage level is a common rated level for flexible cables under the UL62 standard, which can cover the voltage requirements of most industrial power and control signals; the 2000V power frequency withstand voltage is more than 3 times the rated voltage, leaving sufficient safety margin to avoid insulation breakdown caused by voltage fluctuations and instantaneous overvoltage, thus ensuring electrical safety.

[0020] Preferably, the long-term allowable operating temperature range of the cable is -40℃ to 105℃. The lower limit of -40℃ ensures that the cable still has good bending performance in cold environments, avoiding low-temperature brittleness of the sheath and insulation layer; the upper limit of 105℃ corresponds to the UL-certified high-temperature cable standard, which can meet the long-term operating requirements of high-temperature environments such as inside equipment and computer rooms, significantly improving the cable's applicable scenarios and service life.

[0021] This invention also provides a method for preparing a UL-certified high-temperature resistant and flame-retardant power signal composite cable. The method comprises the following steps: Step 1, using a wire drawing and annealing process to prepare power conductors and signal conductors of corresponding cross-sectional areas. The purpose of this step is to process the coarse copper rod to the target wire diameter conductor through drawing, and to eliminate processing stress through annealing, thereby improving the conductor's flexibility and conductivity, and ensuring that the conductor's DC resistance meets standard requirements.

[0022] Step two involves extruding PVC insulation layers onto the outside of the power conductor and signal conductor respectively using an extrusion process to produce power insulated core wires and signal insulated core wires. The purpose of this step is to form a continuous and uniform insulating coating layer on the conductor surface, achieving electrical isolation between the conductors, which is a core process for ensuring the insulation performance of the cable.

[0023] Preferably, in step two, the extrusion temperature range of the PVC insulation layer is 150℃ to 180℃, and segmented water cooling is used for cooling and shaping after extrusion. When the extrusion temperature is below 150℃, the PVC material is not fully plasticized, the surface of the extruded insulation layer is rough and contains pores, and both the insulation and mechanical properties do not meet the standards. When the extrusion temperature is above 180℃, the PVC material is prone to thermal decomposition, the material properties decrease, and the extruded melt has excessive fluidity, making it difficult to control the uniformity of the insulation layer thickness. The segmented water cooling method can avoid the internal stress caused by sudden cooling of the insulation layer through gradient cooling, prevent the insulation layer from cracking and uneven shrinkage, and ensure the dimensional stability and mechanical properties of the insulation layer.

[0024] Step three involves twisting the two insulated signal core wires together. After twisting, an inner layer of polyester insulating tape is wrapped around the wire, followed by braiding tinned copper wire to form a braided shielding layer, and finally, an outer layer of polyester insulating tape is wrapped around the wire to create the shielded signal core unit. The purpose of this step is to complete the twisting and shielding structure of the signal core wires, forming a complete signal transmission unit and ensuring the anti-interference capability of signal transmission.

[0025] Preferably, in step three, the tin-plated copper wire braided shield is processed using a high-speed braiding machine, with a braiding pitch of 8 to 12 times the outer diameter of the shielding layer and a braiding density of not less than 80%. When the braiding pitch is less than 8 times the outer diameter of the shielding layer, the braiding density is too high, resulting in low processing efficiency, large material consumption, and a stiffer shielding layer, reducing the flexibility of the signal line unit. When the braiding pitch is greater than 12 times the outer diameter of the shielding layer, the braiding coverage is insufficient, the shielding effectiveness is reduced, and the 80% density requirement cannot be met. This range allows for a balance between processing efficiency and cable flexibility while ensuring shielding performance.

[0026] Step four involves simultaneously feeding multiple power-insulated core wires and shielded signal core units into a cabling machine for stranding. During the cabling process, cotton thread is filled into the gaps between the core wires to form fillers. After cabling is completed, non-woven fabric is wrapped around the core to form a general wrapping layer, resulting in the cable core assembly. The purpose of this step is to strand all the core wires according to the design arrangement into a complete cable core. The filling and wrapping ensure the roundness and structural stability of the cable core, providing a regular matrix for subsequent sheath extrusion.

[0027] Step five involves extruding a PVC outer sheath layer onto the outside of the cable core assembly using an extrusion process. After cooling, shaping, performance testing, and surface printing, the finished cable is obtained. The purpose of this step is to form a continuous outer sheath protective layer on the outside of the cable core and to ensure, through factory testing, that the various performance indicators of the finished cable meet design and standard requirements.

[0028] Preferably, in step five, the extrusion temperature range of the PVC outer sheath is 160℃~190℃. The extrusion temperature of the sheath is slightly higher than that of the insulation layer because the sheath layer is thicker and requires a higher temperature to ensure that the material is fully plasticized, thereby improving the smoothness and mechanical strength of the sheath surface. The setting logic of the lower and upper limits of the temperature range is consistent with that of the insulation layer, taking into account both plasticization quality and material thermal stability.

[0029] Preferably, the finished products undergo sequential testing of conductor DC resistance, power frequency withstand voltage, and flame retardant performance. The purpose of these tests is to verify the conductor's conductivity, overall insulation safety performance, and flame retardant safety performance, ensuring that all products leaving the factory meet the corresponding UL certification requirements.

[0030] This invention integrates power supply and signal transmission functions into a single cable through a composite design combining a power insulated core wire and a shielded signal core wire unit, reducing wiring space and construction costs. The tinned copper wire braided shielding combined with a double-layer polyester insulation tape effectively blocks electromagnetic interference from the power line to the signal line, ensuring signal transmission stability. The entire system utilizes a 105℃ flame-retardant PVC material system, coupled with a compliant and well-structured cabling and sheath, meeting UL certification requirements for high temperature resistance and VW-1 flame retardancy. The entire structure employs common processing techniques in the cable industry, using standard cable materials within the UL certification system. The process is mature and controllable, suitable for industrial mass production.

[0031] Beneficial effects The present invention has the following beneficial effects: (1) The UL certified high temperature flame retardant power signal composite cable and its preparation method, through the set power insulated core wire and shielded signal core wire unit composite cable structure, can integrate power supply and shielded signal transmission functions in a single cable, solve the problems of large space occupation, high construction cost and easy electromagnetic interference of traditional split cable laying, and achieve the effect of integrated wiring and high stability signal transmission.

[0032] (2) The UL certified high temperature flame retardant power signal composite cable and its preparation method, by setting a high temperature flame retardant PVC material system and a compliant cable core protection structure, can improve the overall thermal aging resistance and flame retardant self-extinguishing performance of the cable, solve the problem that the temperature resistance level of ordinary PVC cable is insufficient and the flame retardant performance is poor and cannot meet the UL certification requirements, and achieve the effect of long-term high temperature stable operation and compliance with flame retardant safety performance.

[0033] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the cross-sectional structure of a UL-certified high-temperature resistant and flame-retardant power signal composite cable according to the present invention. Figure 2 This is a schematic diagram of the power insulation core wire in a UL-certified high-temperature resistant and flame-retardant power signal composite cable of the present invention; Figure 3 This is a schematic diagram of the shielded signal core unit in a UL-certified high-temperature resistant and flame-retardant power signal composite cable of the present invention. Figure 4 This is a flowchart illustrating a UL-certified high-temperature resistant and flame-retardant power signal composite cable manufacturing method according to the present invention.

[0035] In the diagram: 1. Outer sheath layer; 2. Power insulated core wire; 21. Power insulation layer; 22. Power conductor; 3. Shielded signal core unit; 31. Signal insulated core wire; 32. Signal conductor; 33. Braided shielding layer; 4. Filler; 5. Overall wrapping layer. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] This embodiment provides a UL-certified high-temperature resistant and flame-retardant power signal composite cable and its preparation method. For example... Figure 1-4 As shown, the cable includes a cable core assembly and an outer sheath 1 extruded onto the outside of the cable core assembly. The cable core assembly includes three power-insulated core wires 2, a set of shielded signal core units 3, a filler 4, and a total wrapping tape layer 5. The three power-insulated core wires 2 and the set of shielded signal core units 3 are arranged circumferentially to form the cable core body. The filler 4 fills the internal gaps of the cable core body, and the total wrapping tape layer 5 wraps around the outside of the cable core body and the filler 4. Each power-insulated core wire 2 consists of a power conductor 22 and a power insulation layer 21 extruded onto the outside of the power conductor 22. The power conductor 22 is an annealed soft copper conductor with a cross-sectional area of ​​4.0 mm². 2 The power insulation layer 21 is made of 105℃ flame-retardant PVC material. The shielded signal core unit 3 consists of, from the inside out, a twisted pair, an inner insulating strip, a braided shielding layer 33, and an outer insulating strip. Each twisted pair is composed of two signal insulated core wires 31 twisted together. Each signal insulated core wire 31 consists of a signal conductor 32 and a signal insulation layer extruded onto the outside of the signal conductor 32. The signal conductor 32 is an annealed soft copper conductor with a cross-sectional area of ​​0.5 mm². 2 The signal insulation layer is made of 105℃ flame-retardant PVC material; both the inner and outer isolation strips are made of polyester tape; the braided shielding layer 33 is a tin-plated copper wire braided shielding layer with a braiding density of 85%. The filler 4 is a cotton thread filler; the main wrapping layer 5 is a non-woven fabric wrapping layer; and the outer sheath layer 1 is a 105℃ flame-retardant PVC sheath layer.

[0039] The preparation method of UL-certified high-temperature resistant and flame-retardant power signal composite cable includes the following steps: Step 1, using a wire drawing and annealing process to prepare cables with a cross-sectional area of ​​4.0 mm². 2 The power conductor 22 has a cross-sectional area of ​​0.5 mm². 2The signal conductor 32. Step 2: Extrusion process is used to wrap 105℃ grade flame-retardant PVC insulation layer on the outside of the power conductor 22 and the signal conductor 32 respectively. The extrusion temperature range is 170℃~180℃. After extrusion, segmented water cooling is used for cooling and shaping to obtain the power insulated core wire 2 and the signal insulated core wire 31. Step 3: The two signal insulated core wires 31 are twisted together. After twisting, the inner layer of polyester isolation tape is wrapped around, the tinned copper wire is braided using a high-speed braiding machine to form a braided shielding layer 33, and the outer layer of polyester isolation tape is wrapped around to obtain the shielded signal core unit 3. The braiding pitch is 8 times the outer diameter of the shielding layer, and the braiding density is 85%. Step 4: The three power insulated core wires 2 and the shielded signal core unit 3 are simultaneously fed into the cabling machine for twisting and shaping. During the cabling process, cotton thread is filled into the gaps between the cable cores to form filler 4. After the cabling is completed, non-woven fabric is wrapped around to form the total wrapping layer 5 to obtain the cable core assembly. Step 5: A 105°C flame-retardant PVC outer sheath layer 1 is extruded onto the outside of the cable core assembly using an extrusion process. The extrusion temperature range is 180°C to 190°C. After cooling and shaping, performance testing, and surface printing, the finished cable is obtained.

[0040] Example 2

[0041] This embodiment provides a UL-certified high-temperature resistant and flame-retardant power signal composite cable and its preparation method. The main structure and material composition of this cable are completely consistent with those of Embodiment 1, the difference being that the preparation process parameters are taken from the lower limit of the range defined in the claims.

[0042] The preparation method of UL-certified high-temperature resistant and flame-retardant power signal composite cable includes the following steps: Step 1, using a wire drawing and annealing process to prepare cables with a cross-sectional area of ​​4.0 mm². 2 The power conductor 22 has a cross-sectional area of ​​0.5 mm². 2The signal conductor 32. Step 2: Using an extrusion process, a 105℃ flame-retardant PVC insulation layer is extruded onto the outside of the power conductor 22 and the signal conductor 32 respectively. The extrusion temperature range is 150℃~160℃. After extrusion, the conductor is cooled and shaped by segmented water cooling to obtain the power insulated core wire 2 and the signal insulated core wire 31. Step 3: The two signal insulated core wires 31 are twisted together. After twisting, an inner layer of polyester isolation tape is wrapped around them, a braided shielding layer 33 is formed by braiding tinned copper wire using a high-speed braiding machine, and an outer layer of polyester isolation tape is wrapped around them to obtain the shielded signal core unit 3. The braiding pitch is 12 times the outer diameter of the shielding layer, and the braiding density is 80%. Step 4: The three power insulated core wires 2 and the shielded signal core unit 3 are simultaneously fed into a cabling machine for twisting and shaping. During the cabling process, cotton thread is filled into the gaps between the cable cores to form filler 4. After cabling is completed, non-woven fabric is wrapped around them to form a total wrapping layer 5, thus obtaining the cable core assembly. Step 5: A 105°C flame-retardant PVC outer sheath layer 1 is extruded onto the outside of the cable core assembly using an extrusion process. The extrusion temperature range is 160°C to 170°C. After cooling and shaping, performance testing, and surface printing, the finished cable is obtained.

[0043] Comparative Example 1 This comparison example uses a standard PVC power cable, consisting of three 4.0mm² cross-sectional area wires. 2 It consists of a power insulated core wire, cotton thread filler, non-woven fabric wrapping tape, and a PVC outer sheath; it does not integrate a signal core structure. Both the insulation layer and the outer sheath are made of ordinary PVC material rated for 70℃, without any high-temperature resistance or flame-retardant modification design. Its manufacturing process employs conventional cable extrusion cabling technology, with insulation extrusion temperature ranging from 140℃ to 150℃ and sheath extrusion temperature ranging from 150℃ to 160℃.

[0044] Comparative Example 2 This comparative example is a simple power signal composite cable, consisting of three 4.0mm² cross-sectional area wires. 2 It consists of a power insulated core wire and a set of unshielded signal core wires; the signal core wires are composed of only two single-insulated core wires twisted together, without an inner insulating strip, braided shielding layer, or outer insulating strip structure; the gaps between the core wires are not regularly filled, and the outer sheath is made of 70°C grade ordinary PVC material. Its manufacturing process omits the braided shielding process, and the rest adopts the conventional cable extrusion cabling process.

[0045] Experiment Example 1: High Temperature Aging Resistance and Flame Retardant Performance Verification Test The core objective of this test is to verify the synergistic advantages of the UL-certified high-temperature flame-retardant power signal composite cable of this invention in terms of long-term thermal aging stability and flame-retardant safety performance.

[0046] The test items and execution standards are as follows: Thermal aging performance of insulation and sheath layers: forced aging method in air oven, in accordance with the standards UL62-2018 (R2023) "Safety Standard for Flexible Wires and Cables" and UL2556:2021 (R2026) "Test Methods for Wires and Cables"; Vertical burning performance: VW-1 rating vertical burning test, conforming to standard UL1581:2023 "Reference Standard for Wires, Cables and Cords". Test subjects: Five segments of finished cables prepared according to Examples 1, 2, Comparative Example 1, and Comparative Example 2 were selected, each with an effective length of 1m. After being placed in a standard environment of 23℃±2℃ for 24 hours, parallel tests were conducted, and the results were taken as the arithmetic mean. The test results are shown in the table below:

[0047] Test Results Analysis: Examples 1 and 2 significantly outperformed Comparative Examples 1 and 2 in terms of heat aging performance retention and flame retardant self-extinguishing performance. Example 1, using the upper limit of the extrusion temperature range and a smaller braiding pitch, achieved more complete plasticization of the insulation and sheath materials, a denser shielding structure, and optimal overall temperature resistance and flame retardant performance. Example 2, using the lower limit of the process parameters range, with materials and main structure identical to Example 1, still achieved excellent temperature resistance and flame retardant effects, meeting UL certification requirements. Comparative Example 1 used ordinary PVC material at 70℃ without high-temperature resistance and flame retardant modification. After aging at 105℃, the material's mechanical properties significantly deteriorated, and it exhibited ignitable dripping during combustion, failing to meet the VW-1 flame retardant requirements of UL certification. Comparative Example 2, a simple composite structure, also used ordinary PVC substrate, with temperature resistance and flame retardant performance only slightly better than Comparative Example 1, still far below the performance level of this invention. This invention, through the combination of a high-temperature resistant and flame-retardant PVC material system and a well-organized cable structure, achieves dual compliance with both long-term working stability at 105℃ and VW-1 flame retardant safety performance.

[0048] Experiment Example 2: Verification Test of Electrical Insulation and Signal Shielding Performance The core objective of this test is to verify the performance advantages of the UL-certified high-temperature resistant and flame-retardant power signal composite cable of this invention in terms of electrical insulation safety and signal transmission anti-interference.

[0049] The test items and execution standards are as follows: Power frequency withstand voltage performance: Power frequency AC withstand voltage test between conductor and sheath, in accordance with standard UL62-2018 (R2023) "Safety Standard for Flexible Wires and Cables"; 20℃ Insulation Resistance: DC volume insulation resistance test, in accordance with standard UL62-2018 (R2023) "Safety Standard for Flexible Wires and Cables"; Signal shielding attenuation: Shielding effectiveness test using the triaxial tube-in-tube method, in accordance with standard IEC62153-4-7:2021 / AMD1:2025 "Metallic cables and other passive components - Test methods - Part 4-7: Electromagnetic compatibility - Triaxial tube-in-tube method". Test subjects: Samples from the same batch as in Experiment 1. Five 1m long finished cables were taken from each group for parallel testing. The shielding attenuation test frequency was 100MHz, and the results were taken as the arithmetic mean. The test results are shown in the table below:

[0050] Test Result Analysis: Examples 1 and 2 are significantly superior to Comparative Examples 1 and 2 in terms of electrical insulation strength and signal shielding effectiveness. Example 1 uses the upper limit extrusion process, resulting in a uniform and dense plasticized insulation layer. Combined with a higher braiding density, the insulation performance is stable and can withstand a stable 2000V power frequency voltage. The shielding attenuation reaches 32dB at 100MHz, effectively suppressing electromagnetic crosstalk between the power line and the signal line. Example 2 uses the lower limit process parameters, yet the insulation and shielding layers still meet the standards, maintaining a high level of insulation and shielding performance. Comparative Example 1 is a conventional power cable without signal transmission and shielding design, and the withstand voltage level of the ordinary PVC insulation layer is relatively low. Comparative Example 2's signal core lacks a braided shielding structure, resulting in extremely poor signal anti-interference capability. Furthermore, the insulation layer process is rudimentary, and the withstand voltage performance cannot meet the UL certification requirements for a rated voltage of 600V. This invention, through a composite integrated design of the power core and the shielded signal core, simultaneously achieves the dual functions of power supply and high-interference-resistant signal transmission within a single cable.

[0051] 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.

[0052] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A UL-certified high-temperature resistant and flame-retardant power signal composite cable, characterized in that, Includes the cable core assembly and the outer sheath layer extruded on the outside of the cable core assembly (1); The cable core assembly includes multiple power insulated core wires (2), at least one set of shielded signal core units (3), filler (4), and a total wrapping layer (5). Multiple power insulated core wires (2) and at least one set of shielded signal core units (3) are arranged circumferentially to form the cable core body. The filler (4) fills the internal gap of the cable core body. The total wrapping layer (5) wraps around the outside of the cable core body and the filler (4). Each of the aforementioned power-insulated core wires (2) consists of a power conductor (22) and a power insulation layer (21) extruded on the outside of the power conductor (22); The shielded signal core unit (3) is provided with a twisted pair, an inner isolation strip, a braided shielding layer (33) and an outer isolation strip from the inside to the outside. The twisted pair is composed of two signal insulated core wires (31) twisted together. Each signal insulated core wire (31) is composed of a signal conductor (32) and a signal insulation layer extruded on the outside of the signal conductor (32).

2. The UL-certified high-temperature resistant and flame-retardant power signal composite cable according to claim 1, characterized in that, The cross-sectional area of ​​the power conductor (22) is 4.0 mm². 2 The power insulation layer (21) is a PVC insulation layer.

3. The UL-certified high-temperature resistant and flame-retardant power signal composite cable according to claim 1, characterized in that, The cross-sectional area of ​​the signal conductor (32) is 0.5 mm². 2 The signal insulation layer is made of PVC material; the inner and outer isolation strips are both made of polyester tape; the braided shielding layer (33) is a tin-plated copper wire braided shielding layer with a braiding density of ≥80%.

4. The UL-certified high-temperature resistant and flame-retardant power signal composite cable according to claim 1, characterized in that, The filler (4) is a cotton thread filler; the main wrapping layer (5) is a non-woven fabric wrapping layer; and the outer sheath layer (1) is a PVC sheath layer.

5. The UL-certified high-temperature resistant and flame-retardant power signal composite cable according to claim 1, characterized in that, The cable has a rated operating voltage of 600V and a power frequency withstand voltage of 2000V for 5 minutes without breakdown.

6. The UL-certified high-temperature resistant and flame-retardant power signal composite cable according to claim 1, characterized in that, The long-term permissible operating temperature range of the cable is -40℃ to 105℃.

7. A method for preparing a UL-certified high-temperature resistant and flame-retardant power signal composite cable, characterized in that, The method for preparing a UL-certified high-temperature resistant and flame-retardant power signal composite cable according to any one of claims 1 to 6 includes the following steps: Step 1: The power conductor (22) and signal conductor (32) with corresponding cross-sectional areas are prepared by wire drawing and annealing process. Step 2: PVC insulation layers are extruded onto the outside of the power conductor (22) and the signal conductor (32) respectively by extrusion process to obtain the power insulated core wire (2) and the signal insulated core wire (31). Step 3: Twist the two signal insulated core wires (31) together. After twisting, wrap the inner layer of polyester isolation tape, braid the tinned copper wire to form a braided shielding layer (33), and wrap the outer layer of polyester isolation tape to obtain the shielded signal core unit (3). Step 4: Multiple power insulated core wires (2) and shielded signal core units (3) are simultaneously fed into the cable forming machine for stranding and forming. During the cable forming process, cotton thread is filled into the gaps between the cable cores to form filler (4). After the cable forming is completed, non-woven fabric is wrapped around to form a total wrapping layer (5) to obtain the cable core assembly. Step 5: A PVC outer sheath layer (1) is extruded onto the outside of the cable core assembly through an extrusion process. After cooling and shaping, performance testing and surface printing, the finished cable is obtained.

8. The method for preparing a UL-certified high-temperature resistant and flame-retardant power signal composite cable according to claim 7, characterized in that, In step two, the extrusion temperature range of the PVC insulation layer is 150℃~180℃, and after extrusion, it is cooled and shaped by segmented water cooling.

9. The method for preparing a UL-certified high-temperature resistant and flame-retardant power signal composite cable according to claim 7, characterized in that, In step three, the tin-plated copper wire braided shield is processed by a high-speed braiding machine, with a braiding pitch of 8 to 12 times the outer diameter of the shielding layer and a braiding density of not less than 80%.

10. The method for preparing a UL-certified high-temperature resistant and flame-retardant power signal composite cable according to claim 7, characterized in that, In step five, the extrusion temperature range of the PVC outer sheath is 160℃~190℃, and the finished product undergoes a conductor DC resistance test, a power frequency withstand voltage test, and a flame retardant performance sampling inspection in sequence.

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