Pressurized flame-retardant low-intermodulation feeder

Abstract

The utility model discloses a booster-level flame-retardant low-intermodulation feeder line, and relates to the technical field of cables. The booster-level flame-retardant low-intermodulation feeder line comprises an inner conductor, an insulating layer, an outer conductor and a sheath which are coaxially arranged from inside to outside, the outer conductor is a spiral corrugated metal tube, the insulating layer is made of low-density polytetrafluoroethylene with a fibrous microporous structure, and the sheath is made of booster-level flame-retardant fluorinated ethylene propylene; the booster-level flame-retardant low-intermodulation feeder line provided by the utility model has the characteristics of high temperature resistance, high flame retardance, high shielding, low loss, low passive intermodulation and super-flexible bending, is suitable for booster-level cables or cable assemblies of a UL system, and is particularly suitable for interlayers of ceilings and high-flame-retardant safe application occasions of super-flexible wiring connection.

Description

Technical Field

[0001] This utility model relates to the field of cable technology, and in particular to a booster-grade flame-retardant low intermodulation feeder. Background Technology

[0002] In building design and construction, there are power supply systems for the overall design, as well as central air conditioning systems for heating, cooling, and ventilation. In addition, modern information cabling systems require that every desk in every office be connected to the communication system in order to access devices such as telephones, fax machines, data terminals, and computers. In order to make the building aesthetically pleasing, all of the above-mentioned pipeline systems are laid in the form of concealed conduits and wires in the ceiling partition, and communication cables are often laid together with the air conditioning system pipes.

[0003] In the past, communication cables in buildings were concealed within ceiling partitions without regard to high-temperature resistance. However, when central air conditioning system ducts were present in the ceiling partitions, they could affect nearby communication cables. In the event of a fire, it is crucial to ensure that equipment immediately begins collecting data upon receiving a fire alarm and transmits it to a safe location to guarantee the integrity of the information. Furthermore, the burning of cables generates large amounts of toxic gases and smoke, significantly hindering evacuation and posing a safety hazard. Therefore, high-temperature resistant and flame-retardant cables play a vital role in data backup and the safety of life and property. Moreover, the sheer number and complexity of cables within buildings necessitate that communication cables be flexibly routed within limited spaces and possess high shielding, low loss, and low passive intermodulation characteristics for daily use. Utility Model Content

[0004] This application provides a booster-grade flame-retardant low intermodulation feeder suitable for applications in UL systems with booster-grade flame-retardant ratings.

[0005] The booster-grade flame-retardant low intermodulation feeder provided in this application includes, from the inside out, an inner conductor, an insulation layer, an outer conductor, and a sheath arranged coaxially, wherein the outer conductor is a spiral corrugated metal tube;

[0006] The insulating layer is low-density polytetrafluoroethylene with a fibrous microporous structure.

[0007] The sheath is made of pressurized flame-retardant perfluoroethylene propylene.

[0008] Optionally, the ratio of the diameter of the inner conductor, the outer diameter of the insulating layer, and the outer diameter of the outer conductor is (0.8~2.8):(2.2~7.5):(3.2~10.0).

[0009] Optionally, the spiral corrugated metal tube has a wall thickness of 0.11mm to 0.25mm, a crest of 3.2mm to 10.0mm, a trough of 2.1mm to 7.1mm, and a pitch of 1.3mm to 3.6mm.

[0010] Optionally, the spiral corrugated metal tube is made of copper or aluminum.

[0011] Optionally, the inner conductor is a soft round copper wire, copper-clad aluminum wire, silver-plated copper wire, or silver-plated copper-clad aluminum wire.

[0012] Optionally, the insulating layer is formed by wrapping at least two layers of low-density polytetrafluoroethylene film raw material tape, with each layer having an overlap rate of not less than 20%, and adjacent wrapping layers having opposite directions.

[0013] Optionally, the density of the low-density polytetrafluoroethylene is 0.4~0.7 g / cm³. 3 .

[0014] Optionally, the oxygen index of the pressurized flame-retardant polytetrafluoroethylene propylene is not less than 95%.

[0015] Optionally, the thickness of the sheath is not less than 0.45 mm.

[0016] Optionally, the operating temperature of the booster stage flame-retardant low intermodulation feeder is -55~200℃.

[0017] The technical solution of this application has the following beneficial effects:

[0018] The booster-grade flame-retardant low intermodulation feeder provided in this application adopts a low-density polytetrafluoroethylene (PTFE) wrapped insulation, a spiral corrugated outer conductor, and a booster-grade flame-retardant sheath structure. The low-density PTFE wrapped insulation features low dielectric loss, minimal impact from temperature and signal frequency variations, excellent temperature resistance, and good weather resistance. The fully enclosed spiral corrugated metal tube outer conductor serves as a shielding layer, effectively shielding against electromagnetic noise interference and making the cable structure more flexible while enhancing its mechanical properties. The booster-grade flame-retardant perfluoropropylene effectively prevents flame spread and also possesses excellent high-temperature resistance, weather resistance, booster-grade flame retardancy, and radiation resistance.

[0019] Therefore, the booster-grade flame-retardant low intermodulation feeder provided in this application has high temperature resistance, high flame retardancy, high shielding, low loss, low passive intermodulation and ultra-flexible bending characteristics, and is suitable for booster-grade cables or cable assemblies in UL systems, especially suitable for high flame-retardant safety applications in ceiling partitions and ultra-flexible wiring connections. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the booster stage flame-retardant low intermodulation feeder provided in an embodiment of this application;

[0022] Figure 2 A schematic cross-sectional view of the booster stage flame-retardant low intermodulation feeder provided in an embodiment of this application.

[0023] Explanation of reference numerals in the attached diagram: 1. Inner conductor; 2. Insulation layer; 3. Outer conductor; 4. Sheath. Detailed Implementation

[0024] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] The booster-grade flame-retardant low intermodulation feeder provided in this application embodiment is suitable for applications in UL system booster-grade flame-retardant rating scenarios; wherein, the booster-grade flame-retardant rating is the highest flame-retardant level with the highest safety requirements in the UL fire protection and flame-retardant standard.

[0026] like Figure 1 and Figure 2 As shown, the booster-grade flame-retardant low intermodulation feeder provided in this application embodiment includes, from the inside out, an inner conductor 1, an insulation layer 2, an outer conductor 3, and a sheath 4 arranged coaxially.

[0027] The inner conductor 1 is a highly conductive metallic conductor, preferably a soft round copper wire, copper-clad aluminum wire, silver-plated copper wire, or silver-plated copper-clad aluminum wire, which serves as the main carrier for signal transmission and conductivity.

[0028] The insulation layer 2 is made of low-density polytetrafluoroethylene with a fibrous microporous structure. The low-density polytetrafluoroethylene wrapping insulation has the characteristics of low dielectric loss and little influence from temperature and signal frequency changes, excellent temperature resistance and good weather resistance, which makes the feeder product have low loss and high temperature resistance.

[0029] In some preferred embodiments, the insulating layer 2 has a density of 0.4~0.7 g / cm³. 3It is made by wrapping low-density polytetrafluoroethylene film raw material tape.

[0030] The overlap ratio and shrinkage of the insulation layer are two important indicators affecting the insulation performance of the conductor. In some embodiments, the insulation layer 2 adopts a multi-layer wrapping structure with no less than two layers, the overlap ratio of each layer is no less than 20%, and the directions of adjacent wrapping layers are opposite, with tight wrapping and no interlayer separation. After the wrapping is completed, the insulated core wire is... The insulation heat shrinkage test lasted for 120 minutes, and the shrinkage amount was no more than 3 mm.

[0031] The outer conductor 3 is a spiral corrugated metal tube, which is made by welding corrugated metal strips; preferably, it is made of copper or aluminum strips; the manufacturing process of the spiral corrugated metal tube mainly consists of wire feeding, strip feeding, tubular forming, welding, traction, corrugation and wire take-up.

[0032] Specifically, the manufacturing process of the spiral corrugated metal tube is as follows:

[0033] After the metal strip is unrolled, the edges are cut and it is rolled into a tube. While rolling it into a tube, a low-density polytetrafluoroethylene (PTFE) wrapped insulated core wire is inserted into the tubular outer conductor metal tube. Then, the outer conductor is welded into a tube body by a continuous argon arc welding machine. At the same time as the argon arc welding, the outer conductor of the metal tube is corrugated by a corrugating machine to form a spiral corrugated outer conductor that meets the design requirements.

[0034] The structural dimensions of the spiral corrugations include crests, troughs, and pitch, designed based on the product's electrical and mechanical performance indicators. The corrugation method for the outer conductor of the spiral corrugated metal tube involves installing an annular corrugating blade on the corrugating mill head, causing the blade to deflect at an angle consistent with the helix angle of the formed spiral. The corrugation of the outer conductor is completed by the high-speed rotating corrugating blade. During corrugation, the structural dimensions and uniformity of the corrugations are ensured by effectively controlling the tension of each part of the production line and the stability of the corrugating equipment, so that the outer conductor forms the spiral crests, troughs, and pitch required by the design.

[0035] The bending performance of the spiral corrugated metal tube outer conductor cable is far superior to that of the traditional annular corrugated metal tube outer conductor cable; therefore, the spiral corrugated metal tube outer conductor cable provided in this application embodiment has ultra-flexible characteristics and is particularly suitable for applications with high bending performance requirements.

[0036] The sheath 4 is made of pressurized flame-retardant polytetrafluoroethylene propylene; preferably, it is made of modified polytetrafluoroethylene propylene with excellent resistance to environmental stress cracking and low melt flow. Its oxygen index is as high as 95%, which can effectively prevent the spread of flames. It also has the advantages of excellent high temperature resistance, weather resistance, pressurized flame retardancy and radiation resistance.

[0037] The feeder product provided in this application embodiment adopts a high-pressure flame-retardant polytetrafluoroethylene sheath, combined with low-density polytetrafluoroethylene wrapping insulation and a spiral corrugated metal tube outer conductor, so that it meets the CMP rating requirements of the highest flame retardant level of UL 910.

[0038] The experimental results of flame retardant performance are as follows: When multiple samples were laid on the horizontal air duct of the device, the flame did not extend beyond 5 feet from the front of the gas Bunsen burner flame. The maximum peak value of the light density was 0.5 and the maximum average density value was 0.15, which proves that the feeder product has excellent flame retardant performance. The average smoke density and peak smoke density are low, and it can quickly form a barrier when a fire occurs, effectively preventing the spread of flames and effectively reducing the risk of fire.

[0039] In some preferred embodiments, the ratio of the diameter of the inner conductor 1, the outer diameter of the insulating layer 2, and the outer diameter of the outer conductor 3 is (0.8~2.8):(2.2~7.5):(3.2~10.0).

[0040] In some preferred embodiments, the ratio of the diameter of the inner conductor 1, the outer diameter of the insulating layer 2, and the outer diameter of the outer conductor 3 is 1:(2.68~2.75):(3.57~4).

[0041] In some preferred embodiments, the outer conductor 3 is made of a spiral corrugated metal tube with a wall thickness of 0.11 mm to 0.25 mm, crests of 3.2 mm to 10.0 mm, troughs of 2.1 mm to 7.1 mm, and a pitch of 1.3 mm to 3.6 mm.

[0042] In some preferred embodiments, the thickness of the sheath 4 is not less than 0.45 mm.

[0043] The booster-grade flame-retardant low intermodulation feeder provided in this application has an operating temperature range of -55~200℃.

[0044] Furthermore, using a conventional booster-type braided feeder as a comparative example (named RF400P braided feeder), the booster-grade flame-retardant low intermodulation feeder (named RF375-50 feeder) provided in some embodiments of this application was tested with the comparative example according to MIL-DTL-17, and the test results are shown in Table 1.

[0045]

[0046] Table 1. Comparison between this embodiment and a traditional booster cable.

[0047] According to the test results in Table 1, when comparing the same outer diameter specifications, the RF375-50 boosted flame-retardant low intermodulation feeder prepared in this application embodiment has significantly improved temperature resistance, passive intermodulation, shielding effectiveness, loss and bending characteristics compared with the traditional RF400P boosted braided feeder.

[0048] Specifically, the booster-grade flame-retardant low intermodulation feeder adopts a fully enclosed shielding structure with a spiral corrugated metal tube outer conductor to replace the aluminum foil longitudinal wrapping and metal wire braiding structure of the traditional booster-type braided cable. It has excellent shielding performance, and the shielding attenuation is improved from Class B shielding level of not less than 80dB of the traditional booster-type braided cable to Class A++ shielding level of not less than 120dB. It can effectively block external electromagnetic interference from entering the cable and reduce the impact of the internal electromagnetic field of the cable on external equipment and the environment.

[0049] The booster-grade flame-retardant low intermodulation feeder has a passive intermodulation of not less than -165dBc, which can significantly reduce passive intermodulation interference in the communication system and help improve the overall performance and signal quality of the communication system.

[0050] The booster-grade flame-retardant low intermodulation feeder loss is reduced by more than 10%, effectively reducing signal loss, supporting higher frequency signal transmission, maintaining signal stability and reliability, and is suitable for higher frequency signal transmission applications.

[0051] The booster-grade flame-retardant low intermodulation feeder operates at temperatures up to 200℃, exhibiting excellent heat resistance and slowing down cable aging, making it suitable for high-temperature applications. It also possesses high flame-retardant properties, effectively preventing flame spread and reducing fire risk.

[0052] The boosted flame-retardant low intermodulation feeder adopts an ultra-flexible structure design with a spiral corrugated outer conductor, which has ultra-soft characteristics and higher mechanical strength than the traditional braided structure, maintaining the stability of the cable structure when the cable is bent, twisted or squeezed in a small space.

[0053] In summary, the booster-grade flame-retardant low intermodulation feeder provided in this application has high temperature resistance, high flame retardancy, high shielding (not less than 120dB), low loss (not less than -165dBc), low passive intermodulation, and ultra-flexible bending characteristics. It is suitable for booster-grade cables or cable assemblies in UL systems, and is particularly suitable for high flame-retardant safety applications such as ceiling partitions and ultra-flexible wiring connections.

[0054] In the process of describing the embodiments of this application, it should be noted that the low-density polytetrafluoroethylene film raw material tape, the metal tape used to prepare the spiral corrugated outer conductor, and the pressure-boosting flame-retardant polytetrafluoroethylene propylene used are all within the scope of the prior art. Such prior art materials have been widely used in related technical fields, and their technical performance and functional characteristics have been fully verified and recognized. Those skilled in the art can purchase them through conventional market channels.

[0055] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A booster-grade flame-retardant low intermodulation feeder, comprising, from the inside out, an inner conductor, an insulating layer, an outer conductor, and a sheath arranged coaxially, characterized in that, The outer conductor is a spiral corrugated metal tube; The insulating layer is low-density polytetrafluoroethylene with a fibrous microporous structure. The sheath is made of pressurized flame-retardant perfluoroethylene propylene.

2. The booster stage flame-retardant low intermodulation feeder according to claim 1, characterized in that, The ratio of the inner conductor's diameter, the insulation layer's outer diameter, and the outer conductor's outer diameter is (0.8~2.8):(2.2~7.5):(3.2~10.0).

3. The booster stage flame-retardant low intermodulation feeder according to claim 2, characterized in that, The spiral corrugated metal tube has a wall thickness of 0.11mm to 0.25mm, a crest of 3.2mm to 10.0mm, a trough of 2.1mm to 7.1mm, and a pitch of 1.3mm to 3.6mm.

4. The booster stage flame-retardant low intermodulation feeder according to claim 3, characterized in that, The spiral corrugated metal tube is made of copper or aluminum.

5. The booster-stage flame-retardant low intermodulation feeder according to claim 1, characterized in that, The inner conductor is a soft round copper wire, copper-clad aluminum wire, silver-plated copper wire, or silver-plated copper-clad aluminum wire.

6. The booster stage flame-retardant low intermodulation feeder according to claim 1, characterized in that, The insulating layer is formed by wrapping at least two layers of low-density polytetrafluoroethylene film raw material tape, with each layer having an overlap rate of not less than 20%, and adjacent wrapping layers having opposite directions.

7. The booster stage flame-retardant low intermodulation feeder according to claim 6, characterized in that, The density of the low-density polytetrafluoroethylene is 0.4~0.7 g / cm³. 3 .

8. The booster stage flame-retardant low intermodulation feeder according to claim 1, characterized in that, The oxygen index of the pressurized flame-retardant polytetrafluoroethylene propylene is not less than 95%.

9. The booster stage flame-retardant low intermodulation feeder according to claim 8, characterized in that, The thickness of the sheath is not less than 0.45 mm.

10. The booster-stage flame-retardant low intermodulation feeder according to claim 1, characterized in that, The operating temperature of the booster-stage flame-retardant low intermodulation feeder is -55~200℃.

Images