A phase-stable coaxial cable

Abstract

The invention relates to the field of coaxial cables, and is used to solve the problem that the existing coaxial cables have poor mechanical phase stability and the cost of coaxial cables prepared by a full wrapping method is too high. The invention specifically relates to a phase-stable coaxial cable; the insulating layer material and the outer jacket layer material of the phase-stable coaxial cable are both insulating heat-conductive materials, and both have good high and low temperature resistance, corrosion resistance, insulation performance and thermal conductivity. The heat generated by the coaxial cable during operation can be discharged in time without being deformed by heat, which causes a significant decrease in the mechanical phase stability of the coaxial cable. Moreover, by first wrapping a PTFE microporous tape around the outside of a metal conductor and then injection molding to form an outer jacket, the toughness and mechanical properties of the coaxial cable can be improved, thereby improving its mechanical phase stability. Moreover, the coaxial cable adopts a combination of solid injection molding and wrapping methods, and the coaxial cable prepared has low cost but excellent mechanical phase stability.

Description

Technical Field

[0001] The invention relates to the field of coaxial cables, and in particular to a phase-stable coaxial cable. Background Art

[0002] Coaxial cable can be used to transmit analog and digital signals for a wide variety of applications, the most important of which are television broadcasting, long-distance telephone transmission, short-distance connections between computer systems, and local area networks. Coaxial cable has developed rapidly as a means of transmitting television signals to thousands of households. This is cable television. A cable television system can carry dozens or even hundreds of television channels, and its transmission range can reach tens of kilometers. Coaxial cable has long been an important part of the long-distance telephone network. Today, it faces increasing competition from optical fiber, terrestrial microwave and satellite.

[0003] The existing coaxial cable includes an inner conductor, an intermediate insulating layer, an outer conductor and an outer sheath which are arranged in sequence from the inside to the outside. For such a cable with a multi-layer structure, when it works under high temperature conditions or low temperatures, due to the different expansion and contraction coefficients between the layer structures, gaps are generated between the layers, causing the internal structure of the cable to be loose, thereby greatly reducing the mechanical phase stability of the cable. In addition, if the coaxial cable is prepared by a full wrapping method, there is a disadvantage of excessive manufacturing cost. How to improve the poor mechanical phase stability of the existing coaxial cable and the excessive cost of the coaxial cable prepared by a full wrapping method is the key to the present invention. Therefore, a phase-stable coaxial cable is urgently needed to solve the above problems. Summary of the invention

[0004] In order to overcome the above-mentioned technical problems, the object of the present invention is to provide a phase-stable coaxial cable: high-density polyethylene, insulating thermally conductive filler, polyethylene wax, calcium stearate, dibutyl phthalate, antioxidant 1010 and UV-P are added to a mixer, mixed evenly to obtain a mixture, the mixture is added to a twin-screw extruder for melt extrusion, granulated by a granulator to obtain an insulating thermally conductive material, the insulating thermally conductive material is injection-molded on the surface of a silver-plated copper wire to form a core wire, and then 1-2 layers of aluminum foil are wrapped on the core wire to obtain a metal conductor, and the end of the metal conductor is extended into a coaxial cable forming machine for wrapping with a PTFE microporous tape and injection molding to form an outer sleeve to obtain a phase-stable coaxial cable, thereby solving the problems that the existing coaxial cables have poor mechanical phase stability and the cost of the coaxial cables prepared by all wrapping is too high.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A phase-stable coaxial cable is prepared by the following steps:

[0007] Step 1: Weigh 75-95 parts of high-density polyethylene, 5-25 parts of insulating thermal conductive filler, 1.5-2.5 parts of polyethylene wax, 2-4 parts of calcium stearate, 1.2-1.8 parts of dibutyl phthalate, 1-3 parts of antioxidant 1010 and 1.5-2.5 parts of UV-P according to weight parts, and set aside;

[0008] Step 2: Add high-density polyethylene, insulating thermal conductive filler, polyethylene wax, calcium stearate, dibutyl phthalate, antioxidant 1010 and UV-P into a mixer, and mix well to obtain a mixture;

[0009] Step 3: adding the mixed material into a twin-screw extruder for melt extrusion, and granulating it through a granulator to obtain an insulating thermal conductive material;

[0010] Step 4: Inject the insulating thermal conductive material onto the surface of the silver-plated copper wire to form a core wire, and then wrap 1-2 layers of aluminum foil on the core wire to obtain a metal conductor;

[0011] Step 5: Insert the end of the metal conductor into the threading hole of the coaxial cable forming machine, wrap the end of the PTFE microporous tape on the take-up reel around the metal conductor, then insert it into the threading barrel, and then use a traction machine to pull it forward;

[0012] Step 6: Start the driving motor, the driving motor drives the driving gear to rotate, and then the driving gear drives the transmission disc to rotate on the guide rail through the toothed belt, so that the take-up disc rotates around the metal conductor, and the unwinding motor is started. The unwinding motor rotates to drive the take-up disc to rotate. During the rotation of the take-up disc, the PTFE microporous tape is continuously released and the PTFE microporous tape is wound around the metal conductor;

[0013] Step seven: put the insulating thermal conductive material into the feeding hopper and start the extruder. The running extruder will heat and shear the insulating thermal conductive material entering the extruder through the feeding hopper to form a molten material. The molten material enters the liquid storage chamber through the discharge pipe and flows from the liquid spray hole into the threading barrel, and adheres to the metal conductor wrapped with the PTFE microporous tape. When the metal conductor moves through the inner side of the cooling chamber during the movement of the threading barrel, the molten material on the metal conductor is scraped and smoothed due to the reduction in diameter. Then start the circulating pump. The circulating pump runs to transport the cooling water in the water storage tank through the water inlet to the cooling chamber, and then returns to the water storage tank through the drain port to form circulating cooling water. The cooling water cools and shapes the molten material on the metal conductor, and then is output from the end of the threading barrel to obtain the phase-stable coaxial cable.

[0014] As a further solution of the present invention: the insulating thermally conductive filler is prepared by the following steps:

[0015] A1: Add carbon nanotubes and mixed acid into a three-necked flask equipped with a stirrer and a thermometer, stir and react for 3-4 hours at a temperature of 25-30°C and a stirring rate of 350-450r / min, then vacuum filter, wash the filter cake with distilled water until it is neutral, and then place it in a vacuum drying oven and dry it at a temperature of 50-60°C for 3-5 hours to obtain acidified carbon nanotubes;

[0016] A2: Add the acidified carbon nanotubes, anhydrous ethanol and deionized water into a four-necked flask equipped with a stirrer, a thermometer, an air guide tube, a reflux condenser and a constant pressure dropping funnel, and ultrasonically disperse for 1-2 hours at an ultrasonic frequency of 45-55kHz, then add hydrochloric acid solution dropwise while stirring at a temperature of 25-30°C and a stirring rate of 350-450r / min to adjust the pH to 4-4.5, then add aminopropyltriethoxysilane dropwise while stirring, and control the dropping rate to 1-2 drops / s. After the addition is completed, nitrogen protection is introduced, and then the temperature is raised to 60-65°C and stirred for reaction for 20-30 hours. After the reaction is completed, the reaction product is vacuum filtered, and the filter cake is washed with distilled water until neutral, and then placed in a vacuum drying oven and dried at a temperature of 50-60°C for 3-5 hours to obtain modified carbon nanotubes;

[0017] A3: irradiating the PTFE powder for 40-50 hours under nitrogen protection and a radiation energy of 0.4-0.5 KGy / h to obtain pretreated PTFE powder;

[0018] A4: Add pretreated PTFE powder, acrylic acid, triallyl isocyanurate and 1,4-dioxane into a three-necked flask equipped with a stirrer, a thermometer and an air duct, introduce nitrogen protection, stir and react for 3-4 hours at a temperature of 65-70°C and a stirring rate of 350-450r / min, then add modified carbon nanotubes and continue stirring and reacting for 8-10 hours. After the reaction is completed, vacuum filter the reaction product, wash the filter cake with distilled water 2-3 times, and then place it in a vacuum drying oven and dry it at a temperature of 60-65°C for 8-10 hours to obtain an insulating thermally conductive filler.

[0019] As a further solution of the present invention: the carbon nanotubes and the mixed acid in step A1 are used in a ratio of 1 g: 50-60 mL, the mixed acid is a mixture of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 2-3: 1, the mass fraction of the concentrated sulfuric acid is 98%, and the mass fraction of the concentrated nitric acid is 68%.

[0020] As a further solution of the present invention: the usage ratio of the acidified carbon nanotubes, anhydrous ethanol, deionized water and aminopropyltriethoxysilane in step A2 is 10g:200-250mL:30-40mL:4-10mL, and the mass fraction of the hydrochloric acid solution is 20-25%.

[0021] As a further solution of the present invention: the usage ratio of the pretreated PTFE powder, acrylic acid, triallyl isocyanurate, 1,4-dioxane and modified carbon nanotubes in step A4 is 20g:15-25g:1.2-1.5g:80-100mL:5-15g.

[0022] As a further solution of the present invention: the coaxial cable forming machine comprises a wrapping mechanism and a forming mechanism, the forming mechanism comprises a mounting base and an extruder, the top of the mounting base is equipped with an extruder, the top of the extruder is equipped with a feeding hopper, the bottom of the output end of the extruder is equipped with a discharge pipe, the bottom end of the discharge pipe is connected to the top end of the forming cylinder, the bottom of the barrel of the extruder is equipped with two support columns, the two support columns are located on both sides of the discharge pipe, and the forming cylinder is installed on a support frame;

[0023] The wrapping mechanism includes a water tank and a mounting frame, the mounting frame is installed on the top of the water tank, the mounting frame is installed on the top of the mounting frame, a mounting disk is arranged inside the mounting shell, a threading hole is opened at the center of the mounting disk, a take-up disk is rotatably installed on one side surface of the mounting disk, a PTFE microporous tape is wound on the take-up disk, and a unwinding motor is arranged on the other side surface of the mounting disk, and the output shaft of the unwinding motor passes through the mounting disk and is connected to the take-up disk.

[0024] As a further solution of the present invention: a liquid storage chamber and a cooling chamber are respectively provided at both ends of the inner wall of the forming cylinder, a threading barrel is provided inside the forming cylinder, the liquid storage chamber is connected with the discharge pipe, a plurality of liquid spray holes are opened on the liquid storage chamber, and the plurality of liquid spray holes are connected to the inner cavity of the threading barrel, a water inlet is opened at one end of the cooling chamber away from the discharge pipe, a drain outlet is opened on the top side of one end of the cooling chamber close to the discharge pipe, and the diameter of one end of the threading barrel close to the liquid spray hole is larger than the diameter of the other end away from the liquid spray hole.

[0025] As a further solution of the present invention: a transmission disk is arranged in the inner cavity of the mounting shell, meshing teeth are arranged on the outer side of the transmission disk, the inner side of the transmission disk is connected to the outer side of the mounting disk, the thickness of the transmission disk is greater than the thickness of the mounting disk, a guide rail is installed on the inner side of the mounting shell, and the guide rail is slidably connected at the connection between the transmission disk and the mounting disk.

[0026] As a further solution of the present invention: a driving motor is installed on one side of the mounting frame, and a driving gear is sleeved on the output shaft of the driving motor. The driving gear is located on the inner side of one end of the toothed belt and is meshed with the toothed belt. The inner side of the other end of the toothed belt is sleeved on the transmission disk and is meshed with the transmission disk. A connecting frame is installed on one side of the mounting frame, and a tensioning wheel is rotatably installed inside the connecting frame, and the tensioning wheel abuts against the outer side of the toothed belt.

[0027] As a further solution of the present invention: a circulation pump is installed on the other side of the mounting frame, the output end of the circulation pump is connected to the water inlet through a pipe, the input end of the circulation pump is connected to the water tank through a pipe, and the water tank is connected to the drain through a pipe.

[0028] As a further solution of the present invention: the two support columns are symmetrically arranged on both sides of the top of the mounting shell, the support frame is installed on the mounting frame, and the support frame is erected above the circulating pump.

[0029] Beneficial effects of the present invention:

[0030] The invention discloses a phase-stable coaxial cable, which comprises the following steps: adding high-density polyethylene, insulating heat-conductive filler, polyethylene wax, calcium stearate, dibutyl phthalate, antioxidant 1010 and UV-P into a mixer, mixing uniformly to obtain a mixture, adding the mixture into a twin-screw extruder for melt extrusion, granulating the mixture through a granulator to obtain an insulating heat-conductive material, injection-molding the insulating heat-conductive material onto a surface of a silver-plated copper wire to form a core wire, and then wrapping the core wire with 1 to 2 layers of aluminum foil to obtain a metal conductor, extending the end of the metal conductor into a coaxial cable forming machine to wrap a PTFE microporous tape and injection-molding to form an outer sleeve, thereby obtaining a phase-stable coaxial cable; The raw materials of the insulation layer and the jacket layer of the phase-stable coaxial cable are both insulating heat-conducting materials, and both have good high and low temperature resistance, corrosion resistance, insulation performance and thermal conductivity. The heat generated by the coaxial cable during operation can be discharged in time without being deformed by heat, which causes a significant decrease in the mechanical phase stability of the coaxial cable. Moreover, by first wrapping the PTFE microporous tape around the outside of the metal conductor and then injection molding to form an outer sleeve, the toughness and mechanical properties of the coaxial cable can be improved, thereby improving its mechanical phase stability. Moreover, the coaxial cable adopts a combination of solid injection molding and wrapping, and the resulting coaxial cable has low cost but excellent mechanical phase stability.

[0031] In the process of preparing the coaxial cable, an insulating thermal conductive filler is first prepared. First, the carbon nanotubes are acidified by mixed acid, and a large number of carboxyl groups are introduced on the surface of the carbon nanotube particles to provide active sites to obtain acidified carbon nanotubes. Then, the acidified carbon nanotubes are treated by hydrolyzing aminopropyltriethoxysilane to form silane, and a large number of amino groups, hydroxyl groups and Si-O chains are introduced on the surface of the acidified carbon nanotubes to obtain modified carbon nanotubes. PTFE powder is irradiated. The molecular chain of the irradiated PTFE powder contains a large number of free radicals, which can graft acrylic acid onto the surface to improve its dispersibility. At the same time, a large number of carboxyl groups are introduced, and then reacted with the modified carbon nanotubes. The carboxyl groups on the PTFE powder react with the amino and hydroxyl groups on the modified carbon nanotubes to form a carbon nanotube. The two can be combined together by chemical bonds to obtain an insulating thermally conductive filler. The particle surface of the insulating thermally conductive filler contains a large number of active groups and long chains, which can be well dispersed in high-density polyethylene and enhance its binding force through active groups. PTFE has good high and low temperature resistance, corrosion resistance, weather resistance, non-stickiness and self-lubricating properties, as well as excellent dielectric properties and extremely low friction coefficient. The comprehensive performance is very excellent. Carbon nanotubes have good mechanical properties and thermal conductivity. The modified insulating thermally conductive filler improves the shortcomings of poor dispersibility of the two single substances. Therefore, after being added to high-density polyethylene, it is endowed with good mechanical properties, insulating properties and thermal conductivity, thereby improving the mechanical phase stability of the coaxial cable.

[0032] In the process of preparing the coaxial cable, a coaxial cable forming machine is also used. The end of the metal conductor is inserted into the threading hole of the coaxial cable forming machine, and the end of the PTFE microporous tape on the take-up reel is wound around the metal conductor, and then inserted into the threading barrel. Then, the traction machine is used to pull the metal conductor forward. During the process of the metal conductor being pulled forward, the driving motor is operated to realize the rotation of the metal conductor, and the unwinding motor rotates to make the take-up reel continuously release the PTFE microporous tape, and the PTFE microporous tape is wound around the metal conductor. The insulating heat-conductive material is heated and sheared by an extruder to form a molten material. The molten material enters the liquid storage chamber through a discharge pipe, and flows from the liquid spray hole into the threading barrel, adheres to the metal conductor wound with the PTFE microporous tape, and passes through a cooling chamber. When the diameter is reduced, the molten material on the metal conductor is scraped and smoothed, and then the molten material on the metal conductor is cooled and shaped to obtain the phase-stable coaxial cable; the coaxial cable forming machine continuously wraps the PTFE microporous tape around the metal conductor through a wrapping mechanism, which can fully wrap the metal conductor, improve the toughness of the metal conductor, reduce the probability of cracking, bending and even breaking, and maintain the shape continuously, and then the wound metal conductor is directly injection molded by a molding mechanism, wherein the raw material is an insulating thermal conductive material, and the injection-molded outer sleeve has good mechanical properties and thermal conductivity, which further reduces its shape temperature, and the good thermal conductivity can quickly conduct the heat generated by the coaxial cable, thereby further improving the mechanical phase stability of the coaxial cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below in conjunction with the accompanying drawings.

[0034] Figure 1 It is a structural schematic diagram of the coaxial cable forming machine in the present invention;

[0035] Figure 2 It is a structural schematic diagram of the forming mechanism in the present invention;

[0036] Figure 3 It is a schematic diagram of the internal structure of the forming cylinder in the present invention;

[0037] Figure 4 It is a structural schematic diagram of the wrapping mechanism in the present invention;

[0038] Figure 5 It is a three-dimensional schematic diagram of the wrapping mechanism in the present invention;

[0039] Figure 6 It is a schematic diagram of the internal structure of the wrapping mechanism in the present invention.

[0040] In the figure: 101, mounting base; 102, extruder; 103, feeding hopper; 104, discharge pipe; 105, support column; 106, forming cylinder; 107, support frame; 108, threading barrel; 109, liquid storage chamber; 110, cooling chamber; 111, spray hole; 112, water inlet; 113, drain outlet; 201, water storage tank; 202, mounting frame; 203, mounting plate; 204, threading hole; 205, take-up plate; 206, circulation pump; 207, mounting shell; 208, unwinding motor; 209, driving motor; 210, driving gear; 211, connecting frame; 212, tensioning wheel; 213, toothed belt; 214, transmission plate; 215, guide rail. DETAILED DESCRIPTION

[0041] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0042] This embodiment is a method for preparing an insulating thermally conductive filler, comprising the following steps:

[0043] A1: Add 1g of carbon nanotubes, 50mL of 98% concentrated sulfuric acid and 68% concentrated nitric acid in a volume ratio of 2:1 into a three-necked flask equipped with a stirrer and a thermometer, stir and react for 3h at 25°C and a stirring rate of 350r / min, then vacuum filter, wash the filter cake with distilled water until it is neutral, and then place it in a vacuum drying oven and dry it at 50°C for 3h to obtain acidified carbon nanotubes;

[0044] A2: 10 g of acidified carbon nanotubes, 200 mL of anhydrous ethanol and 30 mL of deionized water were added to a four-necked flask equipped with a stirrer, a thermometer, an air guide tube, a reflux condenser and a constant pressure dropping funnel, and ultrasonically dispersed for 1 h at an ultrasonic frequency of 45 kHz, and then a 20% hydrochloric acid solution was added dropwise while stirring at a temperature of 25°C and a stirring rate of 350 r / min to adjust the pH to 4, and then 4 mL of aminopropyltriethoxysilane was added dropwise while stirring, and the dropping rate was controlled to be 1 drop / s. After the addition was completed, nitrogen protection was introduced, and then the temperature was raised to 60°C and stirred for 20 h. After the reaction was completed, the reaction product was vacuum filtered, and the filter cake was washed with distilled water until neutral, and then placed in a vacuum drying oven and dried at a temperature of 50°C for 3 h to obtain modified carbon nanotubes;

[0045] A3: irradiating the PTFE powder for 40 hours under nitrogen protection and a radiation energy of 0.4 KGy / h to obtain pretreated PTFE powder;

[0046] A4: 20g pretreated PTFE powder, 15g acrylic acid, 1.2g triallyl isocyanurate and 80mL 1,4-dioxane were added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen was introduced for protection. The mixture was stirred for 3h at a temperature of 65°C and a stirring rate of 350r / min. Then, 5g modified carbon nanotubes were added and the stirring reaction was continued for 8h. After the reaction was completed, the reaction product was vacuum filtered, the filter cake was washed twice with distilled water, and then placed in a vacuum drying oven and dried at a temperature of 60°C for 8h to obtain an insulating thermally conductive filler. Example 2

[0047] This embodiment is a method for preparing an insulating thermally conductive filler, comprising the following steps:

[0048] A1: Add 1g of carbon nanotubes, 60mL of 98% concentrated sulfuric acid and 68% concentrated nitric acid in a volume ratio of 3:1 into a three-necked flask equipped with a stirrer and a thermometer, stir and react for 4h at a temperature of 30°C and a stirring rate of 450r / min, then vacuum filter, wash the filter cake with distilled water until it is neutral, and then place it in a vacuum drying oven and dry it at a temperature of 60°C for 5h to obtain acidified carbon nanotubes;

[0049] A2: 10 g of acidified carbon nanotubes, 250 mL of anhydrous ethanol and 40 mL of deionized water were added to a four-necked flask equipped with a stirrer, a thermometer, an air guide tube, a reflux condenser and a constant pressure dropping funnel, and ultrasonically dispersed for 2 h at an ultrasonic frequency of 55 kHz, and then a 25% hydrochloric acid solution was added dropwise while stirring at a temperature of 30 ° C and a stirring rate of 450 r / min to adjust the pH to 4.5, and then 10 mL of aminopropyltriethoxysilane was added dropwise while stirring, and the dropping rate was controlled to be 2 drops / s. After the dropwise addition was completed, nitrogen protection was introduced, and then the temperature was raised to 65 ° C and stirred for 30 h. After the reaction was completed, the reaction product was vacuum filtered, and the filter cake was washed with distilled water until neutral, and then placed in a vacuum drying oven and dried at a temperature of 60 ° C for 5 h to obtain modified carbon nanotubes;

[0050] A3: irradiating the PTFE powder for 50 h under nitrogen protection and a radiation energy of 0.5 KGy / h to obtain pretreated PTFE powder;

[0051] A4: 20g pretreated PTFE powder, 25g acrylic acid, 1.5g triallyl isocyanurate and 100mL 1,4-dioxane were added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen was introduced for protection. The mixture was stirred for 4h at 70°C and a stirring rate of 450r / min. Then 15g modified carbon nanotubes were added and the stirring reaction was continued for 10h. After the reaction was completed, the reaction product was vacuum filtered, the filter cake was washed 3 times with distilled water, and then placed in a vacuum drying oven and dried at 65°C for 10h to obtain an insulating thermally conductive filler. Example 3

[0052] See also Figure 1-6 As shown, this embodiment is a coaxial cable forming machine, including a wrapping mechanism and a forming mechanism, the forming mechanism includes a mounting base 101 and an extruder 102, the extruder 102 is mounted on the top of the mounting base 101, a hopper 103 is mounted on the top of the extruder 102, a discharge pipe 104 is mounted on the bottom of the output end of the extruder 102, the bottom end of the discharge pipe 104 is connected to the top end of a forming barrel 106, two support columns 105 are mounted on the bottom of the barrel of the extruder 102, the two support columns 105 are located on both sides of the discharge pipe 104, and the forming barrel 106 is mounted on a support frame 107;

[0053] A liquid storage chamber 109 and a cooling chamber 110 are respectively provided at both ends of the inner wall of the forming cylinder 106. A threading barrel 108 is provided inside the forming cylinder 106. The liquid storage chamber 109 is connected to the discharge pipe 104. A plurality of liquid spray holes 111 are provided on the liquid storage chamber 109. The plurality of liquid spray holes 111 are all connected to the inner cavity of the threading barrel 108. A water inlet 112 is provided at one end of the cooling chamber 110 away from the discharge pipe 104. A water outlet 113 is provided on the top side of one end of the cooling chamber 110 close to the discharge pipe 104. The diameter of one end of the threading barrel 108 close to the liquid spray hole 111 is larger than the diameter of the other end away from the liquid spray hole 111.

[0054] The wrapping mechanism includes a water storage tank 201 and a mounting frame 202. The mounting frame 202 is mounted on the top of the water storage tank 201. The mounting frame 207 is mounted on the top of the mounting frame 202. A mounting disc 203 is arranged inside the mounting shell 207. A threading hole 204 is opened at the center of the mounting disc 203. A take-up disc 205 is rotatably mounted on one side of the mounting disc 203. The take-up disc 205 is wound with a PTFE microporous tape. A reel 208 is mounted on the other side of the mounting disc 203. The output shaft of the reel 208 passes through the mounting disc 203 and is connected to the take-up disc 205.

[0055] A transmission disc 214 is arranged in the inner cavity of the installation shell 207, and meshing teeth are arranged on the outer side of the transmission disc 214. The inner side of the transmission disc 214 is connected to the outer side of the installation disc 203. The thickness of the transmission disc 214 is greater than the thickness of the installation disc 203. A guide rail 215 is arranged on the inner side of the installation shell 207, and the guide rail 215 is slidably connected to the connection between the transmission disc 214 and the installation disc 203.

[0056] A driving motor 209 is mounted on one side of the mounting frame 202. A driving gear 210 is sleeved on the output shaft of the driving motor 209. The driving gear 210 is located inside one end of a toothed belt 213 and meshed with the toothed belt 213. The other end of the toothed belt 213 is sleeved on the inner side of a transmission disc 214 and meshed with the transmission disc 214. A connecting frame 211 is mounted on one side of the mounting frame 202. A tensioning wheel 212 is rotatably mounted inside the connecting frame 211. The tensioning wheel 212 abuts against the outer side of the toothed belt 213.

[0057] A circulation pump 206 is installed on the other side of the mounting frame 202. The output end of the circulation pump 206 is connected to the water inlet 112 through a pipeline. The input end of the circulation pump 206 is connected to the water storage tank 201 through a pipeline. The water storage tank 201 is connected to the drain 113 through a pipeline.

[0058] The two support columns 105 are symmetrically arranged on both sides of the top of the mounting shell 207 . The support frame 107 is installed on the mounting frame 202 . The support frame 107 is erected above the circulation pump 206 . Example 4

[0059] See also Figure 1-6 As shown, this embodiment is a phase-stable coaxial cable, which is prepared by the following steps:

[0060] Step 1: Weigh 75 parts of high-density polyethylene, 5 parts of the insulating thermal conductive filler from Example 1, 1.5 parts of polyethylene wax, 2 parts of calcium stearate, 1.2 parts of dibutyl phthalate, 1 part of antioxidant 1010 and 1.5 parts of UV-P according to weight parts, and set aside;

[0061] Step 2: Add high-density polyethylene, insulating thermal conductive filler, polyethylene wax, calcium stearate, dibutyl phthalate, antioxidant 1010 and UV-P into a mixer, and mix well to obtain a mixture;

[0062] Step 3: adding the mixed material into a twin-screw extruder for melt extrusion, and granulating it through a granulator to obtain an insulating thermal conductive material;

[0063] Step 4: Inject the insulating thermal conductive material onto the surface of the silver-plated copper wire to form a core wire, and then wrap a layer of aluminum foil on the core wire to obtain a metal conductor;

[0064] Step 5: Insert the end of the metal conductor into the threading hole 204 of the coaxial cable forming machine in Example 3, wrap the end of the PTFE microporous tape on the take-up reel 205 around the metal conductor, and then insert it into the threading barrel 108, and then use the traction machine to pull it forward;

[0065] Step 6: Start the driving motor 209, the driving motor 209 drives the driving gear 210 to rotate, and then the driving gear 210 drives the transmission disk 214 to rotate on the guide rail 215 through the toothed belt 213, so that the take-up disk 205 rotates around the metal conductor, and the unwinding motor 208 is started, the unwinding motor 208 rotates to drive the take-up disk 205 to rotate, and the PTFE microporous tape is continuously released during the rotation of the take-up disk 205, and the PTFE microporous tape is wound around the metal conductor;

[0066] Step 7: Add the insulating heat-conductive material into the hopper 103, start the extruder 102, and the running extruder 102 heats and shears the insulating heat-conductive material entering the extruder 102 through the hopper 103 to form a molten material. The molten material enters the liquid storage chamber 109 through the discharge pipe 104, and flows from the liquid spray hole 111 to the threading barrel 108, and adheres to the metal conductor wrapped with the PTFE microporous tape. When the metal conductor moves through the inner side of the cooling chamber 110 during the movement of the threading barrel 108, the molten material on the metal conductor is scraped and smoothed due to the reduction in diameter. Then, the circulating pump 206 is started. The circulating pump 206 is operated to transport the cooling water in the water storage tank 201 to the cooling chamber 110 through the water inlet 112, and then returns to the water storage tank 201 through the drain port 113 to form circulating cooling water. The cooling water cools and shapes the molten material on the metal conductor, and then is output from the end of the threading barrel 108 to obtain the phase-stable coaxial cable;

[0067] The performance of the phase-stable coaxial cable in Example 4 was tested, and the test results are as follows: the insertion loss change rate is 16.5%, and the mechanical phase fluctuation range is less than 1.25°. Example 5

[0068] See also Figure 1-6 As shown, this embodiment is a phase-stable coaxial cable, which is prepared by the following steps:

[0069] Step 1: Weigh 95 parts of high-density polyethylene, 25 parts of the insulating thermal conductive filler from Example 2, 2.5 parts of polyethylene wax, 4 parts of calcium stearate, 1.8 parts of dibutyl phthalate, 3 parts of antioxidant 1010 and 2.5 parts of UV-P according to weight parts, and set aside;

[0070] Step 2: Add high-density polyethylene, insulating thermal conductive filler, polyethylene wax, calcium stearate, dibutyl phthalate, antioxidant 1010 and UV-P into a mixer, and mix well to obtain a mixture;

[0071] Step 3: adding the mixed material into a twin-screw extruder for melt extrusion, and granulating it through a granulator to obtain an insulating thermal conductive material;

[0072] Step 4: Inject the insulating thermal conductive material onto the surface of the silver-plated copper wire to form a core wire, and then wrap 2 layers of aluminum foil on the core wire to obtain a metal conductor;

[0073] Step 5: Insert the end of the metal conductor into the threading hole 204 of the coaxial cable forming machine in Example 3, wrap the end of the PTFE microporous tape on the take-up reel 205 around the metal conductor, and then insert it into the threading barrel 108, and then use the traction machine to pull it forward;

[0074] Step 6: Start the driving motor 209, the driving motor 209 drives the driving gear 210 to rotate, and then the driving gear 210 drives the transmission disk 214 to rotate on the guide rail 215 through the toothed belt 213, so that the take-up disk 205 rotates around the metal conductor, and the unwinding motor 208 is started, the unwinding motor 208 rotates to drive the take-up disk 205 to rotate, and the PTFE microporous tape is continuously released during the rotation of the take-up disk 205, and the PTFE microporous tape is wound around the metal conductor;

[0075] Step seven: Add the insulating heat-conductive material into the hopper 103, start the extruder 102, and the running extruder 102 will heat and shear the insulating heat-conductive material entering the extruder 102 through the hopper 103 to form a molten material. The molten material enters the liquid storage chamber 109 through the discharge pipe 104, and flows from the spray hole 111 to the threading barrel 108, and adheres to the metal conductor wrapped with the PTFE microporous tape. When the metal conductor moves through the inner side of the cooling chamber 110 during the movement of the threading barrel 108, the molten material on the metal conductor is scraped and smoothed due to the reduction in diameter. Then, the circulating pump 206 is started. The circulating pump 206 is operated to transport the cooling water in the water storage tank 201 to the cooling chamber 110 through the water inlet 112, and then returns to the water storage tank 201 through the drain port 113 to form circulating cooling water. The cooling water cools and shapes the molten material on the metal conductor, and then is output from the end of the threading barrel 108 to obtain the phase-stable coaxial cable.

[0076] The performance of the phase-stable coaxial cable in Example 5 was tested, and the test results are as follows: the insertion loss change rate is 13.5%, and the mechanical phase fluctuation range is less than 1.05°.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0078] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A phase-stable coaxial cable, It is characterized in that The phase-stable coaxial cable is prepared by the following steps: Step 1: Weigh 75-95 parts of high-density polyethylene, 5-25 parts of insulating thermal conductive filler, 1.5-2.5 parts of polyethylene wax, 2-4 parts of calcium stearate, 1.2-1.8 parts of dibutyl phthalate, 1-3 parts of antioxidant 1010 and 1.5-2.5 parts of UV-P according to weight parts and set aside; Step 2: Add high-density polyethylene, insulating thermal conductive filler, polyethylene wax, calcium stearate, dibutyl phthalate, antioxidant 1010 and UV-P into a mixer, and mix well to obtain a mixture; Step 3: adding the mixed material into a twin-screw extruder for melt extrusion, and granulating it through a granulator to obtain an insulating thermal conductive material; Step 4: Inject the insulating thermal conductive material onto the surface of the silver-plated copper wire to form a core wire, and then wrap 1-2 layers of aluminum foil on the core wire to obtain a metal conductor; Step 5: The metal conductor is wrapped with the PTFE microporous tape using a coaxial cable forming machine, and then the insulating thermal conductive material is heated and sheared to form a molten material, and the molten material is wrapped on the metal conductor wrapped with the PTFE microporous tape, and then the molten material on the metal conductor is cooled and formed to obtain the phase-stable coaxial cable; The insulating thermally conductive filler is prepared by the following steps: A1: Add carbon nanotubes and mixed acid into a three-necked flask equipped with a stirrer and a thermometer, stir and react for 3-4 hours at a temperature of 25-30°C and a stirring rate of 350-450r / min, then vacuum filter, wash the filter cake with distilled water until it is neutral, and then place it in a vacuum drying oven and dry it at a temperature of 50-60°C for 3-5 hours to obtain acidified carbon nanotubes; A2: Add the acidified carbon nanotubes, anhydrous ethanol and deionized water into a four-necked flask equipped with a stirrer, a thermometer, an air guide tube, a reflux condenser and a constant pressure dropping funnel, and ultrasonically disperse for 1-2 hours at an ultrasonic frequency of 45-55kHz, then add hydrochloric acid solution dropwise while stirring at a temperature of 25-30°C and a stirring rate of 350-450r / min to adjust the pH to 4-4.5, then add aminopropyltriethoxysilane dropwise while stirring, and control the dropping rate to 1-2 drops / s. After the addition is completed, nitrogen protection is introduced, and then the temperature is raised to 60-65°C and stirred for reaction for 20-30 hours. After the reaction is completed, the reaction product is vacuum filtered, and the filter cake is washed with distilled water until neutral, and then placed in a vacuum drying oven and dried at a temperature of 50-60°C for 3-5 hours to obtain modified carbon nanotubes; A3: irradiating the PTFE powder for 40-50 hours under nitrogen protection and a radiation energy of 0.4-0.5 KGy / h to obtain pretreated PTFE powder; A4: Add pretreated PTFE powder, acrylic acid, triallyl isocyanurate and 1,4-dioxane into a three-necked flask equipped with a stirrer, a thermometer and an air duct, introduce nitrogen protection, stir and react for 3-4 hours at a temperature of 65-70°C and a stirring rate of 350-450r / min, then add modified carbon nanotubes and continue stirring and reacting for 8-10 hours. After the reaction is completed, vacuum filter the reaction product, wash the filter cake with distilled water 2-3 times, and then place it in a vacuum drying oven and dry it at a temperature of 60-65°C for 8-10 hours to obtain an insulating thermally conductive filler.

2. A phase-stable coaxial cable according to claim 1, It is characterized in that The carbon nanotubes and the mixed acid in step A1 are used in a ratio of 1 g:50-60 mL. The mixed acid is a mixture of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 2-3:

1. The mass fraction of the concentrated sulfuric acid is 98%, and the mass fraction of the concentrated nitric acid is 68%.

3. A phase-stable coaxial cable according to claim 1, It is characterized in that The usage ratio of the acidified carbon nanotubes, anhydrous ethanol, deionized water and aminopropyltriethoxysilane in step A2 is 10g: 200-250mL: 30-40mL: 4-10mL, and the mass fraction of the hydrochloric acid solution is 20-25%.

4. A phase-stable coaxial cable according to claim 1, It is characterized in that The usage ratio of the pretreated PTFE powder, acrylic acid, triallyl isocyanurate, 1,4-dioxane and modified carbon nanotubes in step A4 is 20 g: 15-25 g: 1.2-1.5 g: 80-100 mL: 5-15 g.

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