A coating device and coating method for enhancing the antioxidant ability of the entire cross-section of a soft copper conductor

Abstract

The present invention provides a coating device and a coating method for enhancing the antioxidant capacity of the entire cross-section of a soft copper conductor. The device includes an antioxidant liquid storage tank, an alcohol box, a support column, a liquid outlet pipe, an infusion pipe, a spray head, an electric control box, and a motor; the alcohol box is arranged above the antioxidant liquid storage tank through the support column, one end of the liquid outlet pipe is inside the antioxidant liquid storage tank and the other end is connected to the infusion pipe, and the infusion pipe is connected to the spray head; one end inside the alcohol box is provided with an inlet die and the other end is provided with an outlet die, a set of wire guiding wheels is arranged between the inlet die and the outlet die, and the stranded conductor to be coated sprays the coating liquid on the surface of the stranded conductor through the inlet die, the wire guiding wheels, and the outlet die. The present invention uses alcohol with a concentration of 96-97% as a solvent and benzotriazole as a solute to prepare an antioxidant coating liquid according to a mass ratio of 1:1.2-1.6%, and at the same time uses a supporting coating device to coat the soft copper conductor, which can not only prevent the entire cross-section of the soft copper conductor from oxidizing but also prevent the antioxidant from crystallizing out as a white substance.

Description

Technical Field

[0001] The present invention relates to the technical field of cable conductor antioxidant technology, and in particular, to a coating device and a coating method for enhancing the antioxidant capacity of the entire cross-section of a soft copper conductor. Background Art

[0002] Common oxidation situations of existing wire and cable conductors are as follows: When selecting BVR or RV electrical equipment wires for home decoration, industrial installation, or wind power switchgear distribution lines, during cable manufacturing and long-term installation, due to the presence of moisture or mixed gases in the air or pipelines, the inner part of the conductor oxidizes and changes color (red or black); the inner conductor of a copper-core silicone rubber cable turns black about one week after insulation; for mining rubber-sheathed flexible cables, because the rubber formula contains sulfur or sulfur-containing groups, the inner conductor oxidizes and turns red, yellow, purple, or even black, etc.

[0003] The phenomenon of conductor oxidation and blackening is a common quality problem in the cable industry or power transmission and distribution lines. This problem is extremely likely to cause customer complaints and affect the supply and demand relationship. Every year, there are countless returns and quality claims caused by this problem. According to incomplete statistics, various losses reach billions of yuan. Therefore, conductor oxidation is a pain point and a difficult point in the industry. In addition, conductor oxidation and blackening generally occur at the ends, and the thickness of the conductor oxide layer is very thin, with the resistance increasing by about 2%. The oxidized and discolored conductor affects people's vision on the one hand and is an important voucher for engineering acceptance products.

[0004] Therefore, solving the problem of conductor oxidation is an urgent practical problem facing every technical person in the cable industry. Starting from the conductor oxidation mechanism, the most crucial thing is to enhance the antioxidant capacity of the conductor. In practice, methods such as adding antioxidants to drawing fluids and annealing fluids or wrapping the conductor with thin films to isolate air have certain effects, but they cannot fundamentally eliminate the decrease in antioxidant capacity caused by annealing, stranding, and secondary vulcanization of the conductor. Especially for multi-strand soft wire combined conductors, due to the presence of oxygen in the conductor gaps, they are extremely likely to oxidize in a humid environment, and it is very difficult to solve. In addition to formulating special antioxidants, emphasis is also placed on the good volatility and environmental protection of its solvent. The conductor is coated with a thin layer of a liquid mixture to form a protective film similar to a metal chelate, isolating oxygen in the air and preventing copper oxidation reactions, thereby enhancing the antioxidant capacity of the copper conductor and reducing the occurrence of quality problems.

[0005] Therefore, there is an urgent need in the industry for a new technology of a coating device and a coating method for enhancing the antioxidant capacity of the entire cross-section of a soft copper conductor. Summary of the Invention

[0006] To solve the technical problem of conductor oxidation and blackening in the prior art, the present invention provides a coating device and a coating method for enhancing the antioxidant capacity of the entire cross-section of a soft copper conductor. Considering the good volatility and environmental friendliness of its solvent, the conductor is coated with a thin layer of a metal chelate-like protective film through the mixed liquid, isolating oxygen in the air and preventing the copper oxidation reaction, thereby enhancing the antioxidant capacity of the copper conductor and reducing the occurrence of quality problems. Specifically, the present invention uses industrial alcohol with a concentration of 96-97% as the solvent and benzotriazole as the solute. After mixing them in a mass ratio of 1:1.2-1.6%, a unique antioxidant coating liquid for the soft copper conductor bunching process is prepared. At the same time, with the coating device supporting the present invention, by controlling the size, dropping speed, and length of the infusion needle of the liquid outlet pipe, the soft copper conductor is coated, which can not only prevent the entire cross-section oxidation of the soft copper conductor but also prevent the antioxidant from crystallizing out as a white substance.

[0007] To achieve the above object, the present invention provides a coating device for enhancing the antioxidant capacity of the entire cross-section of a soft copper conductor. The coating device includes an antioxidant storage tank, an alcohol box, a support column, a liquid outlet pipe, an infusion pipe, an adjustable alcohol spray head, an electric control box, and a motor.

[0008] The antioxidant storage tank is an open container for storing the antioxidant coating liquid and recovering the excess antioxidant coating liquid.

[0009] The alcohol box is a closed container for spraying the antioxidant coating liquid on the cable soft copper bunching conductor to be coated and collecting the excess antioxidant coating liquid.

[0010] The alcohol box is arranged above the antioxidant storage tank through a support column. One end of the liquid outlet pipe is arranged in the antioxidant storage tank, the other end of the liquid outlet pipe is connected to the infusion pipe, the infusion pipe is connected to the adjustable alcohol spray head, a control valve is arranged on the infusion pipe, and a needle is arranged on the adjustable alcohol spray head.

[0011] One end of the alcohol box in the horizontal direction is provided with an inlet die, the other end is provided with an outlet die, and a set of wire guiding wheels is arranged between the inlet die and the outlet die. The cable soft copper bunching conductor to be coated enters the alcohol box through the inlet die, then enters the outlet die through the wire guiding wheels, and the adjustable alcohol spray head sprays the coating liquid on the surface of the bunching conductor.

[0012] The motor is connected to the liquid outlet pipe for pumping the antioxidant coating liquid to the infusion pipe.

[0013] The electric control box is electrically connected to the motor.

[0014] Further, a hole is provided at the bottom of the alcohol box, and one end of the hole is connected to one end of a reflux pipe. The other end of the reflux pipe is arranged in the antioxidant storage tank, and is used for conveying the collected redundant antioxidant coating liquid in the alcohol box into the antioxidant storage tank for recycling and reuse.

[0015] Further, the adjustable alcohol spray head is one or at least two; when there are two adjustable alcohol spray heads, the other end of the liquid outlet pipe is connected to two infusion pipes through a three-way pipe, and the infusion pipes are connected to a plurality of adjustable alcohol spray heads.

[0016] Further, a drain port is provided at the bottom of the antioxidant storage tank; a liquid level sensor is arranged inside the antioxidant storage tank, and the liquid level sensor is electrically connected to the electric control box.

[0017] The present invention also provides a coating method for antioxidant treatment of a stranded cable soft copper conductor. After the stranded cable soft copper conductor to be coated is conveyed to the inlet die of the alcohol box of the above coating device, it enters the alcohol box, and then passes through a wire guiding pulley. The adjustable alcohol spray head sprays the coating liquid on the surface of the stranded conductor through the infusion pipe, and at the same time adjusts the liquid outlet speed to match the stranding speed. Finally, the stranded conductor enters the outlet die, and the coating is completed.

[0018] The antioxidant coating liquid comprises benzotriazole and alcohol, the alcohol concentration is 96 - 97%, and the mass percentage of benzotriazole is 1.2 - 1.6% of the mass of alcohol.

[0019] Further, the infusion pipe is a hospital infusion pipe, and the dripping speed is 1 - 3 drops per second.

[0020] Further, the angle between the adjustable alcohol spray head and the coating liquid sprayed on the stranded conductor is 45 - 55°.

[0021] Further, the size of the needle head is 0.3 - 0.6 mm; the length of the needle head is 1.5 - 3 mm.

[0022] Further, the adjustable alcohol spray head is an infusion needle head; the infusion needle head includes special, No. 7, No. 6, and No. 5 needle heads. Among them, the diameter of the special needle head is 0.6 mm, the diameter of the No. 7 needle head is 0.51 mm, the diameter of the No. 6 needle head is 0.34 mm, and the diameter of the No. 5 needle head is 0.30 mm.

[0023] Further, the stranded cable soft copper conductor to be coated is a stranded wire of the 5th or 6th class soft copper conductor for wire and cable; the specification of the soft copper wire is 0.15 - 0.5 mm.

[0024] The present invention has the following beneficial effects:

[0025] The present invention uses industrial alcohol with a concentration of 96 - 97% as a solvent and benzotriazole as a solute. After mixing them in a ratio of 1:1.2 - 1.6%, a unique antioxidant coating solution for the stranding process of soft copper conductors is prepared. At the same time, the coating device supporting the present invention is used to coat the soft copper conductors by controlling the size of the liquid outlet pipe, the opening and closing speed, and the length of the infusion needle. This can not only prevent the full cross-section oxidation of the soft copper conductors but also prevent the white crystal precipitation of the antioxidant. Because when the antioxidant prepared with alcohol with a concentration above 97% in the same ratio as above is prone to a large amount of precipitation and easily clogs the needle, the needle needs to be replaced or cleaned every about 15 minutes, which is not conducive to the continuous production of soft copper conductors. The configuration of the antioxidant for enhancing the cable copper conductor utilizes the formation of covalent bonds and coordination bonds between benzotriazole and copper atoms to form a chain-like metal chelate protective film, isolating oxygen in the air and preventing the copper oxidation reaction, thereby enhancing the antioxidant ability of the copper conductor. Benzotriazole is a crystalline chemical reagent, slightly soluble in water and alcohol. Therefore, the liquid containing benzotriazole must have good volatility and the water content must be limited because the remaining water in the conductor will accelerate its oxidation. Therefore, industrial alcohol is selected as its solvent. The content of benzotriazole should be appropriate. If the content of benzotriazole is too much, it is extremely easy to precipitate as white crystals and stick to the surface of the conductor, affecting the smoothness of the conductor. If the content of benzotriazole is too little, its antioxidant ability will be insufficient and the protection will be lacking. The best effect is achieved in the range of 1.2 - 1.6%.

[0026] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The following will refer to the drawings to further elaborate on the present invention in detail. Brief Description of the Drawings

[0027] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 is a schematic structural diagram of a coating device for enhancing the antioxidant ability of the full cross-section of a soft copper conductor according to the present invention;

[0029] Among them, 1 - antioxidant storage tank, 2 - motor, 3 - liquid outlet pipe, 4 - electric control box, 5 - support column, 6 - alcohol box, 7 - cable soft copper stranded conductor to be coated, 8 - inlet die, 9 - adjustable alcohol spray head, 10 - tee pipe, 11 - infusion pipe, 12 - connector, 13 - outlet die, 14 - wire guiding pulley, 15 - return pipe, 16 - drain port. Detailed Description of the Embodiment

[0030] The following will elaborate on the embodiments of the present invention in detail with reference to the drawings, but the present invention can be implemented in many different ways defined and covered by the claims.

[0031] The object of the present invention is to provide a coating device and a coating method for economically and effectively preventing the antioxidant capacity of the entire cross-section (including inner and outer surfaces) of Class 5 and Class 6 soft copper stranded conductors of cables. Usually, soft copper wires refer to those composed of multiple fine copper wires of the same diameter. According to different cross-sections, the conductor positions are divided into multiple structures such as the inner layer, adjacent outer layer, and outer layer. The so-called entire cross-section of the soft copper wire refers to the general term of the surface, gaps of the single conductors in the outer layer including the adjacent outer layer, and the surface and gaps of the single conductors in the inner layer. After passing through the stranding die, the gaps between the conductors become correspondingly smaller, and the stranding outer diameter becomes smaller, which is beneficial for saving subsequent materials.

[0032] The processing method of stranding multiple soft copper single wires together in the same direction and with the same pitch without distinction is called bunching. In the standard, it is stipulated that Class 5 or Class 6 conductors adopt the bunching method, which is usually used in occasions where relatively soft conductors such as mobile cable conductors are required. According to the size of the conductor cross-section, different numbers of single wires are used for bunching, and then the conductors are stranded by the method of double stranding to obtain a larger cross-section.

[0033] See Figure 1 , the present invention provides a coating device for enhancing the antioxidant capacity of the entire cross-section of soft copper conductors, especially applicable to the processing equipment for assisting the bunching process of Class 5 or Class 6 soft copper conductors of wires and cables. The coating device includes an antioxidant storage tank 1, an alcohol box 6, a support column 5, a liquid outlet pipe 3, an infusion pipe 11, an adjustable alcohol spray head 9, an electric control box 4, and a motor 2.

[0034] The antioxidant storage tank 1 is an open container for storing the antioxidant coating liquid and recovering the excess antioxidant coating liquid;

[0035] The alcohol box 6 is a closed container. An inlet die 8 and an outlet die 13 are provided in the alcohol box 6. A set of wire guiding wheels 14 is provided between the inlet die 8 and the outlet die 13 for spraying the antioxidant coating liquid on the soft copper bunching conductor 7 of the cable to be coated and collecting the excess antioxidant coating liquid.

[0036] The alcohol box 6 is arranged above the antioxidant storage tank 1 through the support column 5. One end of the liquid outlet pipe 3 is arranged in the antioxidant storage tank 1, the other end of the liquid outlet pipe 3 is connected to the infusion pipe 11, and the infusion pipe 11 is connected to the adjustable alcohol spray head 9. The adjustable alcohol spray head 9 is one or at least two; when the adjustable alcohol spray head 9 is at least two, the other end of the liquid outlet pipe 3 is connected to multiple infusion pipes 11 through a three-way pipe 10, and each infusion pipe 11 can also continue to be connected to multiple infusion pipes 11 through a three-way pipe 10, and multiple infusion pipes 11 are connected to multiple adjustable alcohol spray heads 9.

[0037] A control valve is provided on the infusion tube 11, and a needle is provided on the adjustable alcohol spray head 9; the infusion tube 11 is connected to the adjustable alcohol spray head 9 through a connector 12.

[0038] One end of the alcohol box 6 in the horizontal direction is provided with a wire inlet die 8, and the other end is provided with a wire outlet die 13. A set of wire guiding wheels 14 is provided between the wire inlet die 8 and the wire outlet die 13. The cable soft copper stranded conductor 7 to be coated enters the alcohol box 6 through the wire inlet die 8, and then enters the wire outlet die 13 through the wire guiding wheels 14. The adjustable alcohol spray head 9 sprays the coating liquid on the surface of the stranded conductor.

[0039] The motor 2 is connected to the liquid outlet pipe 3 and is used to pump the antioxidant coating liquid to the infusion tube 11; the electric control box 4 is electrically connected to the motor 2.

[0040] A hole is provided at the bottom of the alcohol box 6, and one end of the hole is connected to one end of the return pipe 15. The other end of the return pipe 15 is provided in the antioxidant storage tank 1.

[0041] A drain port 16 is provided at the bottom of the antioxidant storage tank 1. A liquid level sensor is provided inside the antioxidant storage tank 1, and the liquid level sensor is electrically connected to the electric control box 4.

[0042] In a specific embodiment, the antioxidant storage tank 1 is a rectangular stainless steel metal container with an open top, and there is a liquid outlet pipe 3 connected to the motor 2 inside it. The antioxidant storage tank 1 is the main station for storing the antioxidant coating liquid and provides the antioxidant coating liquid for the continuous production of the cable soft copper stranded conductor 7 to be coated. The motor 2 provides power for coating through a switch. The antioxidant coating liquid is pumped from the liquid outlet hole of the motor electric pump through the liquid outlet pipe 3 to the infusion tube 11. The adjustable alcohol spray head 9 sprays the antioxidant coating liquid through the infusion tube 11, the control valve and the needle in sequence, and directly sprays it on the stranded copper conductor. The stranded conductor has two forms of movement in the alcohol box 6 through the wire inlet die 8, the wire outlet die 13 and a set of wire guiding wheels 14: linear movement and spiral movement. Therefore, the antioxidant coating liquid can easily enter around the conductor, including infiltrating the surface of the inner layer conductor. By adjusting the flow rate through the control valve, the spray head is fixed on the support column 5 with a base, so that the antioxidant coating liquid is sprayed on the moving conductor without deviation, that is, it has a positioning effect. At the same time, according to the size of the conductor cross-section, two spray heads (one in front and one behind or one large and one small) or one spray head are selected to work, depending on the effect, to prevent excess antioxidant liquid from remaining on the conductor and not volatilizing completely with moisture, causing insulation blistering. Therefore, the number of drips needs to match the forward speed of the conductor. When the machine stops, the switches of the motor electric pump and the control valve on the infusion tube are both in the closed state, on the one hand, reducing the consumption of the antioxidant coating liquid, and on the other hand, reducing the precipitation of the antioxidant coating liquid.

[0043] In one embodiment, a heating ring is also provided inside the wire outlet die 13. Through low-voltage and high-current heating, the alcohol and moisture on the surface of the stranded conductor passing through it are quickly volatilized to form a dense antioxidant film.

[0044] The electric control box 4 includes a start button, a stop button and a liquid level alarm button. This part of the energized wire controls the motor and the liquid level, making the switch operation convenient. The upper end of the pillar 5 is connected to the alcohol box 6, the middle part is connected to the control box, and a metal gravity balance plate is welded at the lowermost end. The pillar 5 is made of lightweight aluminum alloy material. Among them, the alcohol box 6 can be used to collect the excess dripping antioxidant coating liquid, so as to flow into the antioxidant liquid storage tank 1 through the return pipe 15. There are an inlet die 8 and a wire outlet die 13 at both ends of the alcohol box 6, which have the functions of sizing and preventing the cores of the cable soft copper stranded conductors to be coated from swinging, and there is also a set of upper and lower guide wheels, which play the role of supporting the conductor and restricting the conductor from deviating.

[0045] For the coating method of anti-oxidation of the cable soft copper conductor bunching by using the above coating device, the cable soft copper stranded conductor to be coated enters the alcohol box through the inlet die, then enters the wire outlet die through the wire passing guide wheel, and the coating liquid is sprayed on the surface of the stranded conductor through the adjustable alcohol spray head via the infusion pipe;

[0046] The coating liquid includes benzotriazole and alcohol. The alcohol concentration is 96-97%, and the mass percentage of benzotriazole is 1.2-1.6% of the mass of alcohol.

[0047] Specific implementation method: As Figure 1 shown, several copper conductors pass through the wire dividing plate and enter the bunching die from left to right to form a bunching copper conductor, that is, the cable soft copper stranded conductor to be coated. Then turn on the electric switch and the manual infusion switch. After passing through the positioning guide wheel, pass through the wire outlet die, adjust the position, quantity and dripping speed of the spray head, check the coating condition of the conductor surface and the inner layer, and start the machine after it is normal. The dripping liquid is jointly controlled by the manual control valve and the size of the infusion needle. The angle between the spray head and the conductor is 45-55 degrees. The best position is just before the conductor enters the die and is stranded. There is a little gap between the conductors to facilitate the liquid to infiltrate the conductor surface. The infusion pipe is a hospital infusion pipe. The dripping speed is 1-3 drops per second, and the size of the needle is 0.3-0.6mm; the length of the needle is 1.5-3mm. The adjustable alcohol spray head is an infusion needle; the infusion needle includes a special needle, a No. 7 needle, a No. 6 needle and a No. 5 needle; among them, the diameter of the special needle is 0.6mm, the diameter of the No. 7 needle is 0.51mm, the diameter of the No. 6 needle is 0.34mm, and the diameter of the No. 5 needle is 0.30mm. It is selected according to the size of the soft fine copper wire of 0.15-0.5mm, and the liquid outlet speed is adapted to the stranding speed.

[0048] Due to the increase in pumping pressure by online spraying, the design mode of hospital infusion tubes is adopted for the first time. In particular, the size of the liquid outlet tube, the control of the switching speed, and the length of the infusion needle are all key cores for implementation.

[0049] Furthermore, the switch control requires that the infusion speed drops at 1 - 3 drops per second and should not be higher than 4 - 5 drops per second. Otherwise, there will still be antioxidant residues inside the conductor. After the alcohol volatilizes, the antioxidant adheres to the conductor surface as white crystals, increasing the DC resistance of the conductor.

[0050] Furthermore, there are four types of infusion needles to choose from: special, size 7, size 6, and size 5. They are selected according to the size of the soft fine copper wire with a diameter of 0.15 - 0.5 mm and the number of conductors. For the choice of needle type, special needles and size 7 needles are preferably selected, and the length of the needle is maintained at 1.5 - 3 mm. This can not only maintain a certain pressure of the liquid but also enable the liquid to pass through the needle quickly, preventing the crystallization of benzotriazole from clogging the needle due to conductor coil change, wire breakage, and other accidents, resulting in poor coating effect.

[0051] The present invention will be explained and illustrated below in conjunction with specific embodiments.

[0052] Example 1:

[0053] After transporting the cable soft copper stranded conductor to be coated to the inlet die of the alcohol box in the coating device as Figure 1 described, it enters the alcohol box, and then passes through the wire guiding pulley. The adjustable alcohol spray head sprays the coating liquid on the surface of the stranded conductor through a hospital infusion tube. At the same time, the liquid outlet speed is adjusted to match the stranding speed. Finally, the stranded conductor enters the outlet die, and the coating is completed. The infusion tube is a hospital infusion tube, and the adjustable alcohol spray head is an infusion needle. The length of the needle is maintained at 1.5 - 3 mm. The dripping liquid is jointly controlled by the manual control valve and the size of the infusion needle. The angle between the needle and the coating liquid sprayed on the stranded conductor is 45 - 55°. The best position is just before the conductor enters the die for stranding and combining. There is a little gap between the conductors, which is convenient for the liquid to infiltrate the conductor surface. The dripping speed is 1 - 3 drops per second, the needle is a size 7 needle, and it is selected according to the size of the soft fine copper wire with a diameter of 0.15 - 0.5 mm. The liquid outlet speed is adapted to the stranding speed.

[0054] The antioxidant coating liquid is prepared by mixing benzotriazole and 96% industrial alcohol in a ratio of 1.2:100, and then filled into a special container for fireproof and sealed storage.

[0055] Example 2:

[0056] After transporting the cable soft copper stranded conductor to be coated to the Figure 1After passing through the inlet die of the alcohol box in the coating device described above, it enters the alcohol box, then passes through the wire guiding pulley. The adjustable alcohol spray head sprays the coating liquid on the surface of the stranded conductor through a hospital infusion tube. At the same time, the liquid outlet speed is adjusted to match the stranding speed. Finally, the stranded conductor enters the outlet die, and the coating is completed. The infusion tube is a hospital infusion tube, and the adjustable alcohol spray head is an infusion needle. The length of the needle is maintained at 1.5 - 3 mm. The dripping liquid is jointly controlled by the manual control valve and the size of the infusion needle. The angle between the needle and the coating liquid sprayed on the stranded conductor is 45 - 55°. The best position is just before the stranded conductor enters the die for stranding. There is a little gap between the conductors to facilitate the liquid to infiltrate the surface of the conductor. The dripping speed is 1 - 3 drops per second. The needle is a No. 6 needle, and it is selected according to the size of the fine soft copper wire with a specification of 0.15 - 0.5 mm. The liquid outlet speed is adapted to the stranding speed.

[0057] The antioxidant coating liquid is prepared by mixing benzotriazole and 96% industrial alcohol in a ratio of 1.3:100, and then filled into a special container for fireproof and sealed storage.

[0058] Example 3:

[0059] The cable soft copper stranded conductor to be coated is conveyed to after the inlet die of the alcohol box in the coating device as described in Figure 1 After passing through the inlet die of the alcohol box in the coating device described above, it enters the alcohol box, then passes through the wire guiding pulley. The adjustable alcohol spray head sprays the coating liquid on the surface of the stranded conductor through a hospital infusion tube. At the same time, the liquid outlet speed is adjusted to match the stranding speed. Finally, the stranded conductor enters the outlet die, and the coating is completed. The infusion tube is a hospital infusion tube, and the adjustable alcohol spray head is an infusion needle. The length of the needle is maintained at 1.5 - 3 mm. The dripping liquid is jointly controlled by the manual control valve and the size of the infusion needle. The angle between the needle and the coating liquid sprayed on the stranded conductor is 45 - 55°. The best position is just before the stranded conductor enters the die for stranding. There is a little gap between the conductors to facilitate the liquid to infiltrate the surface of the conductor. The dripping speed is 1 - 3 drops per second. The needle is a No. 5 needle, and it is selected according to the size of the fine soft copper wire with a specification of 0.15 - 0.5 mm. The liquid outlet speed is adapted to the stranding speed.

[0060] The antioxidant coating liquid is prepared by mixing benzotriazole and 96% industrial alcohol in a ratio of 1.4:100, and then filled into a special container for fireproof and sealed storage.

[0061] Example 4:

[0062] The cable soft copper stranded conductor to be coated is conveyed to as described in Figure 1After passing through the wire inlet die of the alcohol cartridge in the coating device described above, the liquid enters the alcohol cartridge, then passes through the wire guiding pulley, and the adjustable alcohol spray head sprays the coating liquid onto the surface of the bunch-stranded conductor through a hospital infusion tube. At the same time, the liquid outlet speed is adjusted to match the stranding speed. Finally, the bunch-stranded conductor enters the wire outlet die, and the coating is completed. The infusion tube is a hospital infusion tube, and the adjustable alcohol spray head is an infusion needle. The length of the needle is maintained at 1.5 - 3 mm. The dripping liquid is jointly controlled by the manual control valve and the size of the infusion needle. The angle between the needle and the coating liquid sprayed on the bunch-stranded conductor is 45 - 55°. The best position is just before the bunch-stranded conductor enters the die for stranding. There is a little gap between the conductors to facilitate the liquid to infiltrate the surface of the conductor. The dripping speed is 1 - 3 drops per second. The needle is a special needle, which is selected according to the size of the soft copper wire with a specification of 0.15 - 0.5 mm, and the liquid outlet speed is adapted to the stranding speed.

[0063] The antioxidant coating liquid is prepared by mixing benzotriazole and 96% industrial alcohol in a ratio of 1.5:100, and then filled into a special container for fireproof and sealed storage.

[0064] Example 5:

[0065] The difference between Example 5 and Example 1 is that the antioxidant coating liquid is prepared by mixing benzotriazole and 96% industrial alcohol in a ratio of 1.6:100, and then filled into a special container for fireproof and sealed storage.

[0066] Comparative Example 1:

[0067] The difference between Comparative Example 1 and Example 1 is that the antioxidant coating liquid used is prepared by mixing benzotriazole and 96% industrial alcohol in a mass ratio of 1.0:100, and the others are the same as in Example 1.

[0068] Comparative Example 2:

[0069] The difference between Comparative Example 2 and Example 1 is that the antioxidant coating liquid used is prepared by mixing benzotriazole and 96% industrial alcohol in a mass ratio of 1.1:100, and the others are the same as in Example 1.

[0070] Comparative Example 3:

[0071] The difference between Comparative Example 3 and Example 1 is that the antioxidant coating liquid used is prepared by mixing benzotriazole and 96% industrial alcohol in a mass ratio of 1.7:100, and the others are the same as in Example 1.

[0072] Comparative Example 4:

[0073] The difference between Comparative Example 4 and Example 1 is that the antioxidant coating solution used is prepared by mixing benzotriazole and 96% industrial alcohol in a mass ratio of 1.8:100, and the others are the same as in Example 1.

[0074] Comparative Example 5:

[0075] The difference between Comparative Example 4 and Example 1 is that the antioxidant coating solution used is prepared by mixing benzotriazole and 96% industrial alcohol in a mass ratio of 2.0:100, and the others are the same as in Example 1.

[0076] Comparative Example 6:

[0077] The difference between Comparative Example 6 and Example 1 is that the dropping speed is 0.5 drops / second, and the others are the same as in Example 1.

[0078] Comparative Example 7:

[0079] The difference between Comparative Example 7 and Example 1 is that the dropping speed is 5 drops / second, and the others are the same as in Example 1.

[0080] Comparative Example 8:

[0081] The difference between Comparative Example 7 and Example 1 is that the selected needle is a No. 4 needle (diameter 0.21 mm), and the others are the same as in Example 1.

[0082] Comparative Example 9:

[0083] The difference between Comparative Example 7 and Example 1 is that the selected needle is larger than the special needle (diameter 0.65 mm), and the others are the same as in Example 1.

[0084] Next, antioxidant performance verification tests were carried out on Examples 1-5 and Comparative Examples 1-9. Whether the soft-stranded conductor does not change color (including turning red, i.e., slight oxidation, turning purple, and turning black, i.e., deep oxidation) after experiencing the first continuous vulcanization of rubber insulation and the second continuous vulcanization of rubber sheath in a steam (steam pressure 15 kg) at 175-200 °C in a vulcanization tube of about 120 meters was used as evidence for the process verification of the effectiveness of the antioxidant.

[0085] Comparative Example 10: A soft copper conductor without antioxidant was taken, labeled as Comparative Example 10, and placed in the vulcanization workshop for extrusion rubber to observe the oxidation time of the conductor.

[0086] Comparative Example 11: A soft copper conductor without antioxidant was taken, labeled as Comparative Example 11, and a vulcanized rubber insulation layer was extruded to observe the oxidation time of the conductor.

[0087] Application Example: Soft copper stranded wires coated in Comparative Examples 1-2 and Examples 1-3 were respectively used to produce a sample of about 500 meters, labeled as Specimens 1-5 respectively. After being vulcanized once to extrude a rubber insulation layer, the conductor oxidation time, whether colored crystalline substances were precipitated on the conductor, and the percentage increase in the conductor resistance ratio were observed and tested for the conductor resistance ratio.

[0088] Application Example: Soft copper stranded wires coated in Examples 4-5 and Comparative Examples 3-9 were respectively used to produce a sample of about 500 meters, labeled as Specimens 6-10 respectively. They underwent secondary vulcanization, that is, extrusion of a rubber insulation layer + rubber sheath, and the conductor oxidation time, whether colored crystalline substances were precipitated on the conductor, and the percentage increase in the conductor resistance ratio were observed and tested for the conductor resistance ratio. The test results are shown in Table 1 (the observation period was 8 months). The experimental results are shown in Table 1 as follows:

[0089] Table 1

[0090]

[0091]

[0092] It can be seen from Table 1 that: by using alcohol with a concentration of 90-97% as the solvent and benzotriazole as the solute, and mixing them in a ratio of 1:1.2-1.6%, a unique antioxidant coating solution for the soft copper conductor bunching process is prepared. At the same time, with the coating device supporting the present invention, by controlling the size of the liquid outlet pipe, the opening and closing speed, and the length of the infusion needle to coat the soft copper conductor, it can not only prevent the full cross-section oxidation of the soft copper conductor but also prevent the antioxidant from precipitating as white substances. Because the configuration of the antioxidant for enhancing the copper conductor of the cable forms covalent bonds and coordination bonds with copper atoms by benzotriazole, and mutually forms a chain-like metal chelate protective film to isolate oxygen in the air, and the copper oxidation reaction will not occur, thereby enhancing the antioxidant ability of the copper conductor. Benzotriazole is a crystalline chemical reagent, slightly soluble in water and alcohol. Therefore, the liquid containing benzotriazole must have good volatility and the water content must be limited because the water remaining in the conductor will accelerate its oxidation. Therefore, industrial alcohol is selected as its solvent. The content of benzotriazole in the antioxidant coating solution is very important. When the content of benzotriazole is too high, it is extremely easy to precipitate as white crystals and stick to the surface of the conductor, affecting the smoothness of the conductor; when the content of benzotriazole is too low, its antioxidant ability will be insufficient and lack of protection. Therefore, the concentration in the range of 1.2-1.6% has the best effect.

[0093] During the coating process, the dropping speed of the antioxidant coating solution is also very important. When the dropping speed is 0.5 drops / second (Comparative Example 6), the bunching speed of the stranded conductor is faster than the dropping speed of the liquid, resulting in some conductors not being dipped in the protective liquid and having an oxidation risk. The conductors coated with the antioxidant are not oxidized. For segmented wires and cables, this increases the problem of customer complaints about conductor oxidation.

[0094] When the dropping speed is 5 drops per second (Comparative Example 7), the speed of the conductor stranded wire is slower than the dropping speed, and liquid overflows from both the inner and outer surfaces of the conductor, forming a saturated dip coating. Part of the overflowed liquid flows back to the receiver, part hangs on the guide wheel, the collective die and the take-up reel, contaminating the production equipment, and part remains inside the conductor. Over time, this will cause the conductor to oxidize and turn black.

[0095] During the coating process, the selection of the needle size of the antioxidant coating liquid is also very important. When the needle is too small, i.e., a needle smaller than No. 5 is selected (Comparative Example 8), the dropping speed can be finely adjusted through a switch. However, although the antioxidant is completely dissolved into a liquid in alcohol to the naked eye, actually benzotriazole is slightly soluble in alcohol, and the excess part is extremely likely to precipitate, clogging the filter membrane at the front end of the syringe needle. Especially when the machine stops unexpectedly and then the switch is turned on again after several minutes, it is found that it is completely blocked and no liquid comes out, and the needle part needs to be cleaned again, resulting in discontinuous production.

[0096] When the needle is too large, i.e., a needle larger than the extra-large needle is selected (Comparative Example 9), just like a large-sized faucet, the antioxidant quickly flows onto the conductor to form a saturated dip coating. Part of the overflowed liquid flows back to the receiver, part hangs on the guide wheel, the collective die and the take-up reel, contaminating the production equipment, and part remains inside the conductor. Over time, this will cause the conductor to oxidize and turn black, and the effect is the same as that of Comparative Example 7.

[0097] In summary, through the above performance tests of different environments and different ratios, it can be found that benzotriazole can be effectively used to prevent the oxidation of the inner and outer layers of soft copper conductors when used for the bunch stranding of the 5th and 6th type conductors of cables, and it is very effective for the primary continuous vulcanization of rubber insulation and the secondary continuous vulcanization of rubber sheath for the conductors coated with antioxidant, without oxidation and color change, fundamentally solving the problems that have plagued the industry.

[0098] Furthermore, in order to optimize the dropping process of the antioxidant and improve the production efficiency and product quality, the following measures can be taken to adjust the position, quantity and dropping speed of the nozzle:

[0099] First, the adjustment of the nozzle position: Specifically, ensure that the nozzle is located at the best position directly above the soft copper conductor before it enters the die for bunch stranding. This can enable the liquid to fully wet the surface of each conductor, while avoiding the liquid from accumulating or flowing unevenly on the conductor. At the same time, according to the arrangement and stranding method of the conductors, appropriately adjust the position of the nozzle so that each conductor can be evenly covered by the liquid.

[0100] Secondly, adjustment of the number of nozzles: Specifically, according to the number and arrangement of conductors, rationally configure the number of nozzles. If there are more conductors or the arrangement is more complex, the number of nozzles can be appropriately increased to ensure that each conductor can be evenly covered with the liquid. Considering production efficiency and cost, rationally select the number of nozzles. Too many nozzles may lead to waste of resources, while too few may affect the uniform distribution of the liquid.

[0101] In addition, adjustment of the dripping speed: Adjust the dripping speed according to the specifications of the conductors and the viscosity of the liquid. For relatively thin copper wires (such as 0.15 - 0.5 mm), the dripping speed should be controlled within the range of 1 - 3 drops per second to ensure that the liquid can be evenly coated on the surface of the conductors.

[0102] Finally, selection of the needle size: Specifically, according to the specifications of the soft and fine copper wires, select the appropriate needle size. Special, No. 7, No. 6, and No. 5 needles each have their applicable scenarios, and should be selected according to the thickness of the copper wire and production requirements. For relatively thin copper wires, it is recommended to use small-sized needles (such as No. 5 or No. 6) to reduce waste of the liquid and improve the uniformity of the coating.

[0103] By the above measures, the position, number, and dripping speed of the nozzles can be effectively adjusted, thereby optimizing the coating effect of the liquid, improving production efficiency and product quality. At the same time, according to the specific situation and experience in actual operation, the process parameters should be continuously adjusted and optimized to achieve the best production effect.

[0104] For further specific embodiments, the dripping speed should be adapted to the stranding speed: The adaptation of the dripping speed to the stranding speed is to ensure that during the stranding process, the surface of the conductor can be evenly covered with the liquid, forming a continuous and uniform coating. To achieve this, the following specific control methods can be adopted: According to the speed matching principle, first, it is necessary to understand the operating speed range of the stranding machine and select the appropriate dripping speed according to this speed range. Generally, the dripping speed should be slightly lower than the stranding speed to ensure that the liquid has enough time to form a uniform coating on the conductor.

[0105] In a specific factual example, the dripping speed should be adapted to the stranding speed according to the thickness of the coating formed by dripping on the wire. Specifically, when the thickness of the above-mentioned coating is greater than a set threshold value (obtained based on empirical values), the flow rate per unit coating width of the coating liquid passing through the above-mentioned stranded wire is controlled to be constant before and after changing the coating width, and the above-mentioned supply flow rate and the above-mentioned discharge flow rate are controlled to be less than the supply flow rate and the discharge flow rate before changing the coating width. When the thickness of the above-mentioned coating film is less than the thickness of the coating film before changing the coating width, the above-mentioned flow rate is controlled to be constant before and after changing the coating width, and the above-mentioned supply flow rate and the above-mentioned discharge flow rate are controlled to be greater than the supply flow rate and the discharge flow rate before changing the coating width. The above-mentioned supply part has a pump, and the above-mentioned supply flow rate is changed by using this pump. The above-mentioned discharge part has a pump, and the above-mentioned discharge flow rate is changed by using this pump.

[0106] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coating method for enhancing the antioxidant capacity of the entire cross-section of a soft copper conductor, characterized in that, The coating device used in the described coating method includes an antioxidant liquid storage tank, an alcohol box, a support column, a liquid outlet pipe, an infusion pipe, an adjustable alcohol spray head, an electric control box, and a motor; The antioxidant liquid storage tank is an open container for storing the antioxidant coating liquid and recovering the excess antioxidant coating liquid; The alcohol box is a closed container for spraying the antioxidant coating liquid on the cable soft copper stranded conductor to be coated and collecting the excess antioxidant coating liquid; The alcohol box is arranged above the antioxidant liquid storage tank through a support column. One end of the liquid outlet pipe is arranged inside the antioxidant liquid storage tank, the other end of the liquid outlet pipe is connected to the infusion pipe, the infusion pipe is connected to the adjustable alcohol spray head, a control valve is arranged on the infusion pipe, and a needle is arranged on the adjustable alcohol spray head; One end of the alcohol box in the horizontal direction is provided with an inlet die, the other end is provided with an outlet die, and a set of wire guiding wheels is arranged between the inlet die and the outlet die. The cable soft copper stranded conductor to be coated enters the alcohol box through the inlet die, then enters the outlet die through the wire guiding wheels, and the adjustable alcohol spray head sprays the coating liquid on the surface of the stranded conductor; The motor is connected to the liquid outlet pipe and is used to pump the antioxidant coating liquid to the infusion pipe; The electric control box is electrically connected to the motor; After the cable soft copper stranded conductor to be coated is conveyed to the inlet die of the alcohol box in the coating device, it enters the alcohol box, then passes through the wire guiding wheels. The adjustable alcohol spray head sprays the coating liquid on the surface of the stranded conductor through the infusion pipe, and at the same time, adjusts the liquid outlet speed to match the stranding speed. Finally, the stranded conductor enters the outlet die, and the coating is completed; The antioxidant coating liquid includes benzotriazole and alcohol. The alcohol concentration is 90 - 97%, and the mass percentage of benzotriazole is 1.2 - 1.6% of the mass of alcohol; The infusion pipe is a hospital infusion pipe, and the dripping speed is 1 - 3 drops per second; The size of the needle is 0.3 - 0.6 mm; the length of the needle is 1.5 - 3 mm.

2. The coating method according to claim 1, wherein, A hole is arranged at the bottom of the alcohol box, and one end of the hole is connected to one end of a return pipe, and the other end of the return pipe is arranged inside the antioxidant liquid storage tank.

3. The coating method according to claim 1, wherein The adjustable alcohol spray head is one or at least two; when the adjustable alcohol spray head is two, the other end of the liquid outlet pipe is connected to two infusion pipes through a tee pipe, and the infusion pipes are connected to multiple adjustable alcohol spray heads.

4. The coating method according to claim 1, characterized in that, A drain port is arranged at the bottom of the antioxidant liquid storage tank; a liquid level sensor is arranged inside the antioxidant liquid storage tank, and the liquid level sensor is electrically connected to the electric control box.

5. The coating method according to claim 1, characterized in that, The angle between the adjustable alcohol spray head and the coating liquid sprayed on the stranded conductor is 45 - 55°; 6. The coating method according to claim 1, wherein, The adjustable alcohol spray head is an infusion needle; the infusion needle includes a special needle, a No. 7 needle, a No. 6 needle, and a No. 5 needle; among them, the diameter of the special needle is 0.6 mm, the diameter of the No. 7 needle is 0.51 mm, the diameter of the No. 6 needle is 0.34 mm, and the diameter of the No. 5 needle is 0.30 mm.

7. The coating method according to claim 1, characterized in that The cable soft copper stranded conductor to be coated is the stranding of the 5th or 6th class soft copper conductor of wire and cable; the specification of the soft copper wire is 0.15 - 0.5 mm.

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