A photoelectric composite cable with enhanced electromagnetic shielding effect

Abstract

This invention relates to the field of cable manufacturing technology, specifically to a photoelectric composite cable with enhanced electromagnetic shielding. It includes a flat outer sheath, two transversely coaxial cable cores symmetrically arranged at both ends inside the outer sheath, and two longitudinally coaxial optical fiber cores symmetrically arranged in the middle of the outer sheath. The cable cores and optical fiber cores on the same side are jointly covered by a reinforced shielding layer. This photoelectric composite cable features an amorphous internal structure, providing excellent electromagnetic shielding while also exhibiting good flame retardant properties and wear and pressure resistance. It is highly practical and can be used in environments with high electromagnetic interference and harsh conditions.

Description

Technical Field

[0001] This invention relates to the field of cable manufacturing technology, specifically to an optoelectronic composite cable with enhanced electromagnetic shielding effect. Background Technology

[0002] Optical fiber composite cables are a type of composite cable integrating optical fiber and copper conductors, combining the high-speed data transmission capability of optical fiber with the power transmission function of copper conductors. These cables are commonly used in data centers, security monitoring, intelligent transportation systems, and other applications requiring simultaneous data and power transmission. In areas with complex electromagnetic environments, the requirements for electromagnetic interference immunity in optical fiber composite cables are very high, and conventional optical fiber composite cables often fall short in this regard.

[0003] Common methods to avoid electromagnetic interference include increasing the distance from the electromagnetic interference source, adding shielding materials to the outside of the cable, and adding shielding materials inside the cable. External shielding materials are usually copper-clad shielding mesh, which is installed on the outside of the cable. Although this measure can achieve some effect, the overall effect is generally average and its application is relatively limited. It is difficult to achieve good electromagnetic shielding for some non-standard cables. Internal shielding materials are generally mixed with shielding additives. At present, further research is needed on the development of shielding additives and their compatibility with the overall cable, especially with optoelectronic composite cables.

[0004] Patent publication number CN108831618A discloses a highly shielded and impact-resistant medical optoelectronic composite cable, comprising a cable core and an inner sheath, an outer shielding layer, an armor layer, and an outer protective layer sequentially covering the outer side of the cable core. This cable features an outer shielding layer on the outside of the cable core and an inner shielding layer on the signal unit, providing double shielding against signal interference, resulting in high reliability and good stability. However, the shielding layer used in this method is relatively conventional, and its effectiveness needs improvement when applied to optoelectronic composite cables. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides an optical-electric composite cable with enhanced electromagnetic shielding, comprising a flat outer sheath, two transversely coaxial cable cores symmetrically arranged at both ends inside the outer sheath, and two longitudinally coaxial optical fiber cores symmetrically arranged in the middle of the outer sheath.

[0006] The cable core and the optical fiber core located on the same side are jointly covered by a reinforced shielding layer. A reinforcing fixing line is provided between the cable core and the optical fiber core located on the same side. The reinforcing fixing line squeezes the reinforced shielding layer inward, so that the reinforcing fixing line is located between the cable core and the optical fiber core. An auxiliary fixing layer is provided between the two reinforced shielding layers.

[0007] The reinforced shielding layer comprises, by weight, 25-30 parts phenolic resin, 1-2 parts carbon fiber, 2-3 parts boron nitride, 0.5-2.5 parts silicon carbide whiskers, and 5-8 parts modified glass fiber.

[0008] Furthermore, the outer sheath includes an outermost chlorinated polyethylene sheath and an EPDM rubber-based composite liner located inside the chlorinated polyethylene sheath.

[0009] Note: By selecting the best material for the outer sheath, the external structural strength of the optoelectronic composite cable is ensured, guaranteeing a certain level of wear resistance.

[0010] Furthermore, the raw material composition and content of the EPDM rubber-based composite liner, by mass percentage, include 2-5% carbon fiber, 10-20% aluminum nitride powder, and the balance being liquid EPDM rubber.

[0011] Explanation: By optimizing the material of the EPDM rubber-based composite liner, it is made to have a certain electromagnetic shielding effect, thereby improving the overall electromagnetic shielding performance of the electrical composite cable.

[0012] Furthermore, the cable core includes an outermost polyurethane foam sheath, a first steel tape armor layer located inside the polyurethane foam sheath, and an oxygen-free copper conductor located inside the first steel tape armor layer.

[0013] Note: By optimizing the composition of the cable core materials, its structural strength is improved, making it compatible with the overall structure of the optoelectronic composite cable.

[0014] Furthermore, the optical cable core includes an outermost poly(p-butylene terephthalate) sheath, a second steel tape armor layer located inside the poly(p-butylene terephthalate) sheath, and an optical fiber located inside the second steel tape armor layer.

[0015] Note: By optimizing the composition of the optical fiber core, its structural strength is improved, making it compatible with the overall structure of the optoelectronic composite cable.

[0016] Furthermore, the material of the reinforcing fixing line, by weight, includes 7-11 parts epoxy resin and 2-6 parts modified glass fiber; the material of the auxiliary fixing layer, by weight, includes 7-11 parts epoxy resin and 1-4 parts modified glass fiber; each end of the auxiliary fixing layer is provided with an auxiliary fixing line, and the auxiliary fixing line is in contact with the inside of the outer sheath.

[0017] Explanation: By setting up reinforcing fixing lines and auxiliary fixing layers, the structural strength of the optoelectronic composite cable of the present invention is ensured. Combined with the amorphous reinforced shielding layer, it can have good compressive and tensile structural strength while providing efficient electromagnetic shielding.

[0018] Furthermore, the preparation method of the modified glass fiber is as follows: S4 grade high-strength glass fiber is heat-treated in an oven at 550-600℃ for 2-3 hours, then a palmitic acid solution with a mass concentration of 40% is mixed with anhydrous ethanol at a mass ratio of 10-15:100 to obtain a modification solution, the heat-treated S4 grade high-strength glass fiber is completely immersed in the modification solution, the temperature is raised to 42-45℃ and soaked for 1-2 hours, and then dried to obtain the modified glass fiber.

[0019] Explanation: By optimizing the composition of the modified glass fiber, it achieves good structural strength and electromagnetic shielding effect. The modified S4 grade high-strength glass fiber has low carbon content, good compressive and tensile strength, and can achieve good electromagnetic shielding effect when combined with other materials in the reinforced shielding layer. It is applied to the reinforced shielding layer, the reinforced fixing wire, and the auxiliary fixing layer respectively. By adjusting the amount, different uses can be achieved, thus enabling the optoelectronic composite cable of the present invention to have a good electromagnetic shielding effect.

[0020] Furthermore, the method for preparing the optoelectronic composite cable is as follows:

[0021] S1. Cable core preparation: The raw materials of the cable core are co-extruded using an extruder to obtain a linear cable core;

[0022] S2. Optical cable core preparation: The raw materials of the optical cable core are co-extruded using an extruder to obtain a linear optical cable core;

[0023] S3. Preparation of reinforced shielding layer: The raw materials of the reinforced shielding layer are placed together in a mixer and stirred and mixed at 45-50°C for 0.5-1h at a stirring speed of 200-300rpm. Then, the product obtained by mixing is extruded and granulated through a twin-screw extruder to obtain a strip-shaped reinforced shielding layer at an extrusion temperature of 150-200°C.

[0024] S4. Preparation of reinforcing fixing line: The raw materials of the reinforcing fixing line are co-extruded using an extruder to obtain a linear reinforcing fixing line;

[0025] S5. Preparation of auxiliary fixing layer: The raw materials of the auxiliary fixing layer are co-extruded using an extruder to obtain a layered auxiliary fixing layer;

[0026] S6. Co-extrusion molding: The cable core, the optical fiber core, the reinforcing shielding layer, the reinforcing fixing line, and the auxiliary fixing layer are placed symmetrically in pairs and arranged in parallel. The reinforcing fixing line squeezes the reinforcing shielding layer inward, so that the reinforcing fixing line is located between the cable core and the optical fiber core. The auxiliary fixing layer is placed between the two reinforcing shielding layers and arranged closely. Then, the outer sheath is co-extruded around the periphery to obtain the optoelectronic combined cable. The cable exit speed is 1-2 m / min.

[0027] Note: By optimizing the preparation method of the optoelectronic composite cable of the present invention, a tight and firm connection between its various components can be achieved.

[0028] Furthermore, in S6, during co-extrusion molding, continuous steam vulcanization is performed on the exterior of the reinforced shielding layer through a continuous vulcanization pipeline with water vapor balance. The steam vulcanization pressure is controlled at 0.6–0.8 MPa, and the relationship between the steam vulcanization time t and the steam vulcanization temperature T is as follows:

[0029]

[0030] In the formula, K is a constant, taken as 2.3; T1 is the minimum steam vulcanization temperature, taken as 120~140℃; t1 is the steam vulcanization time corresponding to the minimum steam vulcanization temperature, taken as 20min; T2 is the preset steam vulcanization temperature, taken as 160~180℃; t2 is the steam vulcanization time corresponding to the preset steam vulcanization temperature.

[0031] Note: By optimizing and adjusting the preparation parameters for the unique reinforced shielding layer material of this invention, formulas for selecting the steam vulcanization temperature and time during the preparation process are provided, thereby achieving efficient and stable production.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] (1) The photoelectric composite cable with enhanced electromagnetic shielding effect of the present invention is designed with an amorphous structure inside the cable and a series of anti-electromagnetic shielding layer strips or lines are added between each structural layer to form a photoelectric composite cable with high shielding effect. The composition of the modified glass fiber is optimized to give it good structural strength and electromagnetic shielding effect, and it is applied to the reinforced shielding layer, the reinforced fixing line and the auxiliary fixing layer respectively. Different uses are achieved by adjusting the amount, so that the photoelectric composite cable of the present invention has good electromagnetic shielding effect, while also having good flame retardant performance and wear and pressure resistance performance. It is highly practical and can be used in high electromagnetic interference and harsh environments.

[0034] (2) The present invention provides a specific method for the preparation of an optical-electric composite cable with enhanced electromagnetic shielding effect. Due to the use of an amorphous internal structure, there is a gap between the cable outer sheath and the reinforced shielding layer. During the extrusion process, the outer sheath is prone to generate bubbles or burst. Therefore, during production, a continuous vulcanization production line with water vapor balance is selected, the steam pressure is optimized and adjusted, and the most suitable temperature-time relationship formula is selected to make the cable internal and external temperatures uniform, avoid the generation of bubbles and bursts, and finally achieve better structural strength. Attached Figure Description

[0035] Figure 1This is a cross-sectional view of an optoelectronic composite cable with enhanced electromagnetic shielding effect according to the present invention;

[0036] Figure 2 This is a schematic diagram of the electromagnetic interference simulation model of the cable in control group 1 in the experimental example of the present invention;

[0037] Figure 3 This is a schematic diagram of the electromagnetic interference simulation model of the cable in control group 2 in the experimental example of the present invention;

[0038] Figure 4 This is a schematic diagram of the electromagnetic interference simulation model of the cable in control group 3 in the experimental example of the present invention;

[0039] Figure 5 This is a schematic diagram of the cable electromagnetic interference simulation model in Example 10 of the experimental examples of the present invention.

[0040] In the diagram: 1-outer sheath, 11-chlorinated polyethylene sheath, 12-EPDM rubber-based composite inner lining, 2-cable core, 21-polyurethane foam sheath, 22-first steel tape armor layer, 23-oxygen-free copper conductor, 3-optical fiber core, 31-polybutylene terephthalate sheath, 32-second steel tape armor layer, 33-optical fiber, 4-reinforced shielding layer, 5-reinforced fixing wire, 6-auxiliary fixing layer, 61-auxiliary fixing wire. Detailed Implementation

[0041] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.

[0042] Example 1: The description of this example is a photoelectric composite cable with enhanced electromagnetic shielding effect, including a flat outer sheath 1, two transversely coaxial cable cores 2 symmetrically arranged at both ends inside the outer sheath 1, and two longitudinally coaxial optical fiber cores 3 symmetrically arranged in the middle of the outer sheath 1.

[0043] The outer sheath 1 includes an outermost chlorinated polyethylene sheath 11 and an EPDM rubber-based composite liner 12 located inside the chlorinated polyethylene sheath 11. The raw material composition and content of the EPDM rubber-based composite liner 12, by mass percentage, include 3% carbon fiber, 15% aluminum nitride powder, and the remainder is liquid EPDM rubber.

[0044] The cable core 2 includes an outermost polyurethane foam sheath 21, a first steel tape armor layer 22 located inside the polyurethane foam sheath 21, and an oxygen-free copper conductor 23 located inside the first steel tape armor layer 22. The optical cable core 3 includes an outermost poly(terephthalic acid) butylene glycol sheath 31, a second steel tape armor layer 32 located inside the poly(terephthalic acid) butylene glycol sheath 31, and an optical fiber 33 located inside the second steel tape armor layer 32.

[0045] The cable core 2 and optical fiber core 3 located on the same side are covered by a reinforced shielding layer 4. A reinforcing fixing line 5 is provided between the cable core 2 and optical fiber core 3 located on the same side. The reinforcing fixing line 5 squeezes the reinforced shielding layer 4 inward, so that the reinforcing fixing line 5 is located between the cable core 2 and optical fiber core 3. An auxiliary fixing layer 6 is provided between the two reinforced shielding layers 4.

[0046] The reinforced shielding layer 4 is made of the following materials by weight: 27 parts phenolic resin, 1.5 parts carbon fiber, 2.5 parts boron nitride, 1.5 parts silicon carbide whiskers, and 6 parts modified glass fiber.

[0047] The material of the reinforcing fixing line 5, by weight, includes: 8 parts epoxy resin and 4 parts modified glass fiber. The material of the auxiliary fixing layer 6, by weight, includes: 8 parts epoxy resin and 2 parts modified glass fiber. Each end of the auxiliary fixing layer 6 is provided with an auxiliary fixing line 61, and the auxiliary fixing line 61 is in contact with the inside of the outer sheath 1.

[0048] The modified glass fiber is prepared as follows: S4 grade high-strength glass fiber is heat-treated in an oven at 580℃ for 2.5h. Then, a palmitic acid solution with a mass concentration of 40% and anhydrous ethanol are mixed at a mass ratio of 12:100 to obtain a modification solution. The heat-treated S4 grade high-strength glass fiber is completely immersed in the modification solution and heated to 43℃ for 1.5h. After being removed and dried, the modified glass fiber is obtained.

[0049] Example 2: The difference between this example and Example 1 is that the raw material composition and content of the EPDM rubber-based composite liner 12, by mass percentage, include 2% carbon fiber, 10% aluminum nitride powder, and the remainder is liquid EPDM rubber.

[0050] Example 3: The difference between this example and Example 1 is that the raw material composition and content of the EPDM rubber-based composite liner 12, by mass percentage, include 5% carbon fiber, 20% aluminum nitride powder, and the remainder is liquid EPDM rubber.

[0051] Example 4: The difference between this example and Example 1 is that the material of the reinforced shielding layer 4, by weight, includes: 25 parts phenolic resin, 1 part carbon fiber, 2 parts boron nitride, 0.5 parts silicon carbide whiskers, and 5 parts modified glass fiber.

[0052] Example 5: The difference between this example and Example 1 is that the material of the reinforced shielding layer 4, by weight, includes: 30 parts of phenolic resin, 2 parts of carbon fiber, 3 parts of boron nitride, 2.5 parts of silicon carbide whiskers, and 8 parts of modified glass fiber.

[0053] Example 6: The difference between this example and Example 1 is that the material of the reinforcing fixing line 5, by weight, includes 7 parts epoxy resin and 2 parts modified glass fiber, and the material of the auxiliary fixing layer 6, by weight, includes 7 parts epoxy resin and 1 part modified glass fiber.

[0054] Example 7: The difference between this example and Example 1 is that the material of the reinforcing fixing line 5, by weight, includes: 11 parts epoxy resin and 6 parts modified glass fiber, and the material of the auxiliary fixing layer 6, by weight, includes: 11 parts epoxy resin and 4 parts modified glass fiber.

[0055] Note: The reinforcing fixing line 5 and the auxiliary fixing layer 6 mainly serve as auxiliary fixing and secondly as auxiliary electromagnetic shielding. Therefore, it is necessary to ensure their strength while also providing a certain electromagnetic shielding effect. Thus, the amount of modified glass fiber added is controlled at an appropriate level.

[0056] Example 8: The difference between this example and Example 1 is that the modified glass fiber is prepared as follows: S4 grade high-strength glass fiber is placed in an oven at 550°C for 2 hours for heat treatment. Then, a palmitic acid solution with a mass concentration of 40% and anhydrous ethanol are mixed at a mass ratio of 10:100 to obtain a modification solution. The heat-treated S4 grade high-strength glass fiber is completely immersed in the modification solution and heated to 42°C for 1 hour. After being taken out and dried, the modified glass fiber is obtained.

[0057] Example 9: The difference between this example and Example 1 is that the modified glass fiber is prepared as follows: S4 grade high-strength glass fiber is placed in a 600℃ oven for heat treatment for 3 hours. Then, a 40% palmitic acid solution and anhydrous ethanol are mixed at a mass ratio of 15:100 to obtain a modification solution. The heat-treated S4 grade high-strength glass fiber is completely immersed in the modification solution and heated to 45℃ for 2 hours. After being taken out and dried, the modified glass fiber is obtained.

[0058] Example 10: This example is a method for preparing an enhanced electromagnetic shielding optical cable according to Example 1, including the following steps:

[0059] S1. Preparation of cable core 2: The raw materials of cable core 2 are co-extruded using an extruder to obtain a linear cable core 2;

[0060] S2, Optical cable core 3 preparation: The raw materials of optical cable core 3 are co-extruded using an extruder to obtain a linear optical cable core 3;

[0061] S3, Preparation of reinforced shielding layer 4: The raw materials of reinforced shielding layer 4 are placed together in a mixer and stirred and mixed at 46°C for 0.75h at a stirring speed of 250rpm. Then, the product obtained by mixing is extruded and granulated through a twin-screw extruder to obtain strip-shaped reinforced shielding layer 4 at an extrusion temperature of 180°C.

[0062] S4. Preparation of reinforcing fixing line 5: The raw materials of reinforcing fixing line 5 are co-extruded using an extruder to obtain a linear reinforcing fixing line 5;

[0063] S5. Preparation of auxiliary fixing layer 6: The raw materials of auxiliary fixing layer 6 are co-extruded using an extruder to obtain a layered auxiliary fixing layer 6;

[0064] S6. Co-extrusion molding: The cable core 2, optical fiber core 3, reinforced shielding layer 4, reinforcing fixing line 5, and auxiliary fixing layer 6 are placed symmetrically in pairs and parallel to each other. The reinforcing fixing line 5 presses the reinforced shielding layer 4 inward, so that the reinforcing fixing line 5 is located between the cable core 2 and the optical fiber core 3. The auxiliary fixing layer 6 is placed between the two reinforced shielding layers 4 and arranged tightly. Then, the outer sheath 1 is co-extruded around the periphery to form the optical fiber combined cable. The cable exit speed is 1.5m / min. During co-extrusion molding, the outside of the reinforced shielding layer 4 is continuously steam vulcanized through a continuous vulcanization pipe with water vapor balance. The steam vulcanization pressure is controlled at 0.7MPa. The relationship between the steam vulcanization time t and the steam vulcanization temperature T is as follows:

[0065]

[0066] In the formula, K is a constant, taken as 2.3; T1 is the minimum steam vulcanization temperature, taken as 130℃; t1 is the steam vulcanization time corresponding to the minimum steam vulcanization temperature, taken as 20min; T2 is the preset steam vulcanization temperature, taken as 170℃; t2 is the steam vulcanization time corresponding to the preset steam vulcanization temperature.

[0067] Example 11: The difference between this example and Example 10 is that, in S3, preparation of the reinforced shielding layer 4: the raw materials for the reinforced shielding layer 4 are placed together in a mixer and stirred and mixed at 45°C for 0.5 hours at a stirring speed of 200 rpm. Then, the product obtained by mixing is extruded and granulated through a twin-screw extruder to obtain a strip-shaped reinforced shielding layer 4 at an extrusion temperature of 150°C.

[0068] Example 12: The difference between this example and Example 10 is that, in S3, the preparation of the reinforced shielding layer 4: the raw materials for the reinforced shielding layer 4 are placed together in a mixer and stirred and mixed at 50°C for 1 hour at a stirring speed of 300 rpm. Then, the product obtained by mixing is extruded and granulated through a twin-screw extruder to obtain a strip-shaped reinforced shielding layer 4 at an extrusion temperature of 200°C.

[0069] Example 13: The difference between this example and Example 10 is that, in S6, the exit speed in co-extrusion molding is 1m / min. During co-extrusion molding, the outside of the reinforced shielding layer 4 is continuously steam vulcanized through a continuous vulcanization pipe with water vapor balance. The steam vulcanization pressure is controlled at 0.6MPa. T1 is the minimum steam vulcanization temperature, which is 120℃; T2 is the preset steam vulcanization temperature, which is 160℃.

[0070] Example 14: The difference between this example and Example 10 is that, in S6, the exit speed in co-extrusion molding is 2m / min. During co-extrusion molding, the outside of the reinforced shielding layer 4 is continuously steam vulcanized through a continuous vulcanization pipe with water vapor balance. The steam vulcanization pressure is controlled at 0.8MPa. T1 is the minimum steam vulcanization temperature, which is 140℃; T2 is the preset steam vulcanization temperature, which is 180℃.

[0071] Experimental Example: The description of this experimental example is based on the scheme described in Example 10, and aims to illustrate the practical application effect of the present invention.

[0072] 1. Experimental Design: To elucidate the electromagnetic shielding performance of the enhanced electromagnetic shielding optoelectronic composite cable prepared according to this invention, the following experimental group was designed:

[0073] Control group 1: No reinforced shielding layer 4 was installed; the outer sheath 1 was directly wrapped around the cable core 2.

[0074] Control group 2: The outer sheath 1 is directly covered with the reinforced shielding layer 4 and then the cable core 2 is covered;

[0075] Control group 3: The reinforced shielding layer 4 was replaced with a commercially available general electromagnetic shielding layer aluminum-plastic composite tape, and the reinforced fixing wire 5 and the auxiliary fixing layer 6 were replaced with general rubber.

[0076] 2. Relevant Performance Experiments: Electromagnetic interference tests were conducted on cables from control groups 1-3 and Example 10. Interference transmitting cables were placed next to each cable, with a calculated frequency range of 1-250MHz. The interference voltage applied to the transmitting cable was fixed at 1V. The actual performance of the invention under different experimental conditions was compared. The cable length was 3m in all cases. The results are as follows: Figures 2-4 As shown.

[0077] First, there is control group 1, such as... Figure 2 As shown, without enhanced electromagnetic shielding, the voltage coupling value of the cable is relatively high under interference signals in the three bands, with an average value of 0.01V. This is mainly because it is close to the transmitting cable and the coupling effect is strong. If no shielding measures are taken, it will have a serious interference effect on the equipment corresponding to the cable in control group 1.

[0078] Secondly, control group 2, such as Figure 3 As shown, it can be seen that after adding the reinforced shielding layer 4, the voltage coupling value of the cable under the interference signals of the three bands is reduced, and the average interference signal amplitude is 35.5μV, indicating that adding the reinforced shielding layer 4 can achieve a good electromagnetic shielding effect.

[0079] Secondly, control group 3, such as Figure 4 As shown, it can be seen that by using commercially available electromagnetic shielding layer aluminum-plastic composite tape combined with the internal structure of the optoelectronic combined cable of the present invention, a certain electromagnetic shielding effect can also be achieved, but the overall effect is not as good as control group 2 and example 10.

[0080] Finally, there is Example 10, such as... Figure 5 As shown, it can be seen that by adopting the reinforced shielding layer 4 of the present invention and improving the internal structure, the electromagnetic shielding effect is greatly enhanced. The voltage coupling value of the cable is the lowest under the interference signals of the three bands, which can achieve a better electromagnetic shielding effect.

[0081] We then tested other properties of the optoelectronic composite cables in control group 3 and example 10, mainly their tensile strength, elongation at break and bending strength. The specific data are shown in Table 1.

[0082] Table 1. Structural strength tests of the optoelectronic composite cables in control group 3 and example 10.

[0083]

[0084] As can be seen from the data in Table 1, the performance of the optoelectronic composite cable in Example 10 is superior to that of the optoelectronic composite cable using a general electromagnetic shielding layer aluminum-plastic composite tape. This shows that optimizing the composition of the modified glass fiber not only gives it a good electromagnetic shielding effect but also improves its structural strength. The modified S4 grade high-strength glass fiber has a low carbon content and good compressive and tensile strength. At the same time, when combined with other materials in the reinforced shielding layer, it can achieve a good electromagnetic shielding effect. It is applied to the reinforced shielding layer, the reinforced fixing wire, and the auxiliary fixing layer respectively. By adjusting the amount, different uses can be achieved, thus enabling the optoelectronic composite cable of the present invention to have a good electromagnetic shielding effect.

Claims

1. A photoelectric composite cable with enhanced electromagnetic shielding effect, characterized in that, It includes a flat outer sheath (1), two transversely coaxial cable cores (2) symmetrically arranged at both ends inside the outer sheath (1), and two longitudinally coaxial optical fiber cores (3) symmetrically arranged in the middle inside the outer sheath (1). The cable core (2) and the optical fiber core (3) located on the same side are covered by a reinforced shielding layer (4). A reinforcing fixing line (5) is provided between the cable core (2) and the optical fiber core (3) located on the same side. The reinforcing fixing line (5) squeezes the reinforced shielding layer (4) inward, so that the reinforcing fixing line (5) is located between the cable core (2) and the optical fiber core (3). An auxiliary fixing layer (6) is provided between the two reinforced shielding layers (4). The reinforced shielding layer (4) is made of the following materials by weight: 25-30 parts of phenolic resin, 1-2 parts of carbon fiber, 2-3 parts of boron nitride, 0.5-2.5 parts of silicon carbide whiskers, and 5-8 parts of modified glass fiber. The material of the reinforcing fixing line (5) by weight includes: 7-11 parts epoxy resin and 2-6 parts modified glass fiber. The material of the auxiliary fixing layer (6) by weight includes: 7-11 parts epoxy resin and 1-4 parts modified glass fiber. Each end of the auxiliary fixing layer (6) is provided with an auxiliary fixing line (61), and the auxiliary fixing line (61) is in contact with the inside of the outer sheath (1). The modified glass fiber is prepared by: placing S4 grade high-strength glass fiber in an oven at 550-600℃ for 2-3 hours for heat treatment; then mixing a 40% palmitic acid solution with anhydrous ethanol at a mass ratio of 10-15:100 to obtain a modification solution; completely immersing the heat-treated S4 grade high-strength glass fiber in the modification solution; heating to 42-45℃ for 1-2 hours; and then drying to obtain the modified glass fiber. The method for preparing the optoelectronic composite cable is as follows: S1. Cable core (2) preparation: The raw materials of the cable core (2) are co-extruded using an extruder to obtain a linear cable core (2); S2, Optical cable core (3) preparation: The raw materials of the optical cable core (3) are co-extruded using an extruder to obtain a linear optical cable core (3); S3. Preparation of reinforced shielding layer (4): The raw materials of the reinforced shielding layer (4) are placed together in a mixer and stirred and mixed at 45-50°C for 0.5-1h with a stirring speed of 200-300rpm. Then the product obtained by mixing is extruded and granulated through a twin-screw extruder to obtain a strip-shaped reinforced shielding layer (4) with an extrusion temperature of 150-200°C. S4. Preparation of reinforcing fixing line (5): The raw materials of the reinforcing fixing line (5) are co-extruded using an extruder to obtain a linear reinforcing fixing line (5); S5. Preparation of auxiliary fixing layer (6): The raw materials of the auxiliary fixing layer (6) are co-extruded using an extruder to obtain a layered auxiliary fixing layer (6); S6. Co-extrusion molding: The cable core (2), the optical fiber core (3), the reinforced shielding layer (4), the reinforcing fixing line (5), and the auxiliary fixing layer (6) are placed symmetrically in pairs and arranged in parallel. The reinforcing fixing line (5) squeezes the reinforced shielding layer (4) inward, so that the reinforcing fixing line (5) is located between the cable core (2) and the optical fiber core (3). The auxiliary fixing layer (6) is placed between the two reinforced shielding layers (4) and arranged closely. Then, the outer sheath (1) is co-extruded on the outer periphery to obtain the optoelectronic combined cable. The output speed is 1 to 2 m / min.

2. The optoelectronic composite cable with enhanced electromagnetic shielding effect as described in claim 1, characterized in that, The outer sheath (1) includes a chlorinated polyethylene sheath (11) located on the outermost side, and a EPDM rubber-based composite liner (12) located on the inner side of the chlorinated polyethylene sheath (11).

3. The optoelectronic composite cable with enhanced electromagnetic shielding effect as described in claim 2, characterized in that, The raw material composition and content of the EPDM rubber-based composite liner (12) are as follows, by mass percentage: 2-5% carbon fiber, 10-20% aluminum nitride powder, and the remainder is liquid EPDM rubber.

4. The optoelectronic composite cable with enhanced electromagnetic shielding effect as described in claim 1, characterized in that, The cable core (2) includes an outermost polyurethane foam sheath (21), a first steel strip armor layer (22) located inside the polyurethane foam sheath (21), and an oxygen-free copper conductor (23) located inside the first steel strip armor layer (22).

5. The optoelectronic composite cable with enhanced electromagnetic shielding effect as described in claim 1, characterized in that, The optical cable core (3) includes an outermost poly(p-butylene terephthalate) sheath (31), a second steel tape armor layer (32) located inside the poly(p-butylene terephthalate) sheath (31), and an optical fiber (33) located inside the second steel tape armor layer (32).

6. The optoelectronic composite cable with enhanced electromagnetic shielding effect as described in claim 1, characterized in that, In S6, during co-extrusion molding, the exterior of the reinforced shielding layer (4) is continuously steam vulcanized through a continuous vulcanization pipeline with water vapor balance. The steam vulcanization pressure is controlled at 0.6-0.8 MPa. The relationship between the steam vulcanization time t and the steam vulcanization temperature T is as follows: In the formula, K is a constant, taken as 2.3; T1 is the minimum steam vulcanization temperature, taken as 120~140℃; t1 is the steam vulcanization time corresponding to the minimum steam vulcanization temperature, taken as 20min; T2 is the preset steam vulcanization temperature, taken as 160~180℃; t2 is the steam vulcanization time corresponding to the preset steam vulcanization temperature.

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