A continuous production process for flat electromagnetic wire

Abstract

The present invention discloses a continuous production process of flat electromagnetic wire, which belongs to the technical field of electromagnetic wire, and comprises the following steps: the first step is to draw the wire and then calender it twice, and then sizing it through a sizing die to obtain a processed conductor; the second step is to treat the processed conductor with NMT, anneal it, and obtain an annealed conductor; the third step is to wrap it using a double-head wrapping machine; the fourth step is to send the wrapped conductor into a sintering furnace through a guide wheel for sintering, keep the wire material suspended during the sintering process, and then send it to a hot pressing device through a guide wheel for hot pressing and shaping after sintering, and finally wind it up after cooling to obtain a flat electromagnetic wire. When the modified polyetheretherketone is coated on the surface of the conductor, the special siloxane structure is very easy to hydrolyze and then can form hydrogen bonds with the surface of the conductor, thereby improving the adhesion between the polyetheretherketone and the conductor, improving the coating effect, and solving the problem in the prior art that the insulating layer is too thick, which is not conducive to the miniaturization of motors in the current new energy vehicle field.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic wires, and in particular to a continuous production process of flat electromagnetic wires. Background Art

[0002] The motor equipment is the heart of the power device, and the quality of the electromagnetic wire determines the service life of the motor, and the performance of the insulation layer material determines the quality of the electromagnetic wire. At present, the temperature resistance level of the enameled wire with a thinner insulation layer among the common electromagnetic wires in China is up to 240℃. If the motor is to be used in special fields, the temperature resistance level of the electromagnetic wire must be improved, such as using special engineering plastics with high comprehensive performance such as polyphenylene sulfide, polyimide, polyetheretherketone, liquid crystal polymer and polysulfone as insulation materials.

[0003] Using special engineering materials with high temperature resistance as insulating materials is a necessary condition for improving the temperature resistance of electromagnetic wires. As insulating layers, special engineering materials themselves have good wear resistance, radiation resistance, good toughness, high voltage resistance, and long corona resistance. Special electromagnetic wires with a single insulating layer that have been on the market generally use traditional thermal radiation heating to preheat the copper wire to 120-150°C for 8-10s. The copper wire surface is prone to oxidation and blackening, and uneven oxidation, which affects the subsequent adhesion of the insulating layer on the copper wire. In addition, the temperature of the copper wire after preheating cannot be accurately controlled. If the temperature is too low, the insulating layer will crystallize too early on the electromagnetic wire, affecting the performance. If the temperature is too high, the insulating layer will decompose. In the prior art, an intermediate layer is generally coated between the polyetheretherketone insulation layer and the copper conductor, which has good adhesion to the copper conductor and also has good bonding with the polyetheretherketone insulation layer. However, the composite insulation layer will cause the insulation layer of the electromagnetic wire to be thicker, which is not conducive to the current requirements for miniaturization of motors in the field of new energy vehicles. Therefore, how to improve the adhesion between polyetheretherketone and the copper conductor is a technical problem that needs to be solved urgently. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a continuous production process of flat electromagnetic wire.

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

[0006] A continuous production process for flat electromagnetic wires comprises the following steps:

[0007] The first step is to draw the wire and then roll it twice, and then use a sizing die to size it to obtain a processed conductor;

[0008] The second step is to process the processed conductor through NMT treatment (including alkali washing, acid washing, T liquid treatment, pure water ultrasonic cleaning, and drying, which can process nano-scale pits on the surface of the conductor to provide better adhesion for subsequent wrapping film sintering), and then anneal it in a nitrogen atmosphere to obtain an annealed conductor;

[0009] Step 3: evenly mix the modified polyetheretherketone and polyphenylene sulfide in a weight ratio of 7-8:2-3, and then make a wrapping film through a film making machine, and then wrap it with a double-head wrapping machine after slitting;

[0010] The fourth step is to send the wrapped conductor into the sintering furnace through the guide wheel for sintering. During the sintering process, the wire is kept suspended. After sintering, it is sent to the hot pressing equipment through the guide wheel for hot pressing and shaping. Finally, it is cooled by air and then wound up to obtain the flat electromagnetic wire.

[0011] Furthermore, in the third step, the overlapping rate is 50%-55%, and the wrapping direction is S direction.

[0012] Furthermore, in the fourth step, the hot pressing and shaping is performed by two groups of four mutually perpendicular rollers.

[0013] Further, in the third step, the modified polyetheretherketone is prepared by the following steps:

[0014] Step S1, placing polyetheretherketone in a drying oven at 70-85°C for 24 hours, then adding it to dimethyl sulfoxide, stirring it magnetically and adding sodium borohydride, heating it to 100-110°C, stirring it magnetically and reacting it for 20 hours, filtering it after the reaction is completed, washing the filter cake with anhydrous ethanol, 10% dilute hydrochloric acid and deionized water three times respectively, and then drying it at 80°C for 24 hours to obtain hydroxylated polyetheretherketone, and controlling the dosage ratio of polyetheretherketone, sodium borohydride and dimethyl sulfoxide to be 15-20g:5-8g:500mL;

[0015] In step S1, sodium borohydride is used as a reducing agent and dimethyl sulfoxide is used as a solvent, and the ketone carbonyl group on the polyetheretherketone is reduced to a hydroxyl group to prepare a hydroxylated polyetheretherketone.

[0016] Step S2, add the prepared hydroxylated polyetheretherketone to N,N-dimethylformamide, heat to 50-55°C, stir at a uniform speed for 20 hours, add silane-polyethylene glycol-carboxyl (Yusi Pharmaceutical), stir at a uniform speed and add N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine in sequence, heat to 70-75°C, stir at a uniform speed and react for 24 hours to obtain modified polyetheretherketone, and control the dosage ratio of hydroxylated polyetheretherketone, silane-polyethylene glycol-carboxyl, N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine and N,N-dimethylformamide to 2-2.5g:4-6g:9.20-9.36g:0.62-0.68g:50mL.

[0017] In step S2, the hydroxyl group on the hydroxylated polyetheretherketone undergoes an esterification reaction with the carboxyl group on the silane-polyethylene glycol-carboxyl group, and then the siloxane structure on the silane-polyethylene glycol-carboxyl group is connected to the polyetheretherketone structure. When the obtained modified polyetheretherketone is coated on the surface of the conductor, the special siloxane structure is easily hydrolyzed and can form hydrogen bonds with the surface of the conductor, thereby improving the adhesion between the polyetheretherketone and the conductor, improving the coating effect, and making the prepared electromagnetic wire structure more stable.

[0018] Beneficial effects of the present invention:

[0019] The present invention prepares a flat electromagnetic wire, and modified polyetheretherketone is coated on the surface of a conductor. The excellent performance of polyetheretherketone itself brings insulation, corona resistance and other properties to the electromagnetic wire, and the added polyphenylene sulfide has excellent electrical insulation, corrosion resistance and other properties. At the same time, compared with the price of polyetheretherketone, its cost is lower, which can effectively reduce the production cost of the product. In addition, the present invention modifies polyetheretherketone. When the prepared modified polyetheretherketone is coated on the surface of the conductor, the special siloxane structure is easily hydrolyzed and can form hydrogen bonds with the surface of the conductor, thereby improving the adhesion between polyetheretherketone and the conductor, improving the coating effect, and no additional bonding layer is needed, which solves the problem in the prior art that the insulating layer is too thick and is not conducive to the miniaturization of motors in the current new energy vehicle field. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0021] Example 1

[0022] A continuous production process for flat electromagnetic wires comprises the following steps:

[0023] The first step is to draw the copper wire and then roll it twice, and then use a sizing die to size it to obtain a processed conductor;

[0024] The second step is to process the processed conductor through NMT treatment (including alkali washing, acid washing, T liquid treatment, pure water ultrasonic cleaning, and drying, which can process nano-scale pits on the surface of the conductor to provide better adhesion for subsequent wrapping film sintering), and then anneal it in a nitrogen atmosphere to obtain an annealed conductor;

[0025] Step 3: Evenly mix the modified polyetheretherketone and polyphenylene sulfide in a weight ratio of 7:3, and make a wrapping film through a film-making machine, and then wrap it with a double-head wrapping machine after slitting;

[0026] The fourth step is to send the wrapped conductor into the sintering furnace through the guide wheel and sinter it at 360°C. During the sintering process, the wire is kept suspended. After sintering, it is sent to the hot pressing equipment through the guide wheel for hot pressing and shaping. Finally, it is cooled by air and then wound up to obtain the flat electromagnetic wire.

[0027] In the third step, the overlap rate is 50%, and the wrapping direction is S.

[0028] In the fourth step, hot pressing and shaping are completed by two groups of four mutually perpendicular rollers.

[0029] In the third step, the modified polyetheretherketone is prepared by the following steps:

[0030] Step S1, placing polyetheretherketone in a drying oven at 70°C and drying for 24 hours, then adding it to dimethyl sulfoxide, magnetically stirring and adding sodium borohydride, heating to 100°C, magnetically stirring and reacting for 20 hours, filtering after the reaction, washing the filter cake with anhydrous ethanol, 10% by mass dilute hydrochloric acid and deionized water three times respectively, and then drying it at 80°C for 24 hours to obtain hydroxylated polyetheretherketone, and controlling the dosage ratio of polyetheretherketone, sodium borohydride and dimethyl sulfoxide to be 15g:5g:500mL;

[0031] Step S2, add the prepared hydroxylated polyetheretherketone to N,N-dimethylformamide, heat to 50°C, stir at a uniform speed for 20 hours, add silane-polyethylene glycol-carboxyl (Yusi Pharmaceutical), stir at a uniform speed and add N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine in sequence, heat to 70°C, stir at a uniform speed and react for 24 hours to obtain modified polyetheretherketone, and control the dosage ratio of hydroxylated polyetheretherketone, silane-polyethylene glycol-carboxyl, N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine and N,N-dimethylformamide to 2g:4g:9.20g:0.62g:50mL.

[0032] Example 2

[0033] A continuous production process for flat electromagnetic wires comprises the following steps:

[0034] The first step is to draw the copper wire and then roll it twice, and then use a sizing die to size it to obtain a processed conductor;

[0035] The second step is to process the processed conductor through NMT treatment (including alkali washing, acid washing, T liquid treatment, pure water ultrasonic cleaning, and drying, which can process nano-scale pits on the surface of the conductor to provide better adhesion for subsequent wrapping film sintering), and then anneal it in a nitrogen atmosphere to obtain an annealed conductor;

[0036] Step 3: Evenly mix the modified polyetheretherketone and polyphenylene sulfide in a weight ratio of 7:3, and make a wrapping film through a film-making machine, and then wrap it with a double-head wrapping machine after slitting;

[0037] The fourth step is to send the wrapped conductor into the sintering furnace through the guide wheel and sinter it at 370°C. During the sintering process, the wire is kept suspended. After sintering, it is sent to the hot pressing equipment through the guide wheel for hot pressing and shaping. Finally, it is cooled by air and then wound up to obtain the flat electromagnetic wire.

[0038] In the third step, the overlap rate is 50%, and the wrapping direction is S.

[0039] In the fourth step, hot pressing and shaping are completed by two groups of four mutually perpendicular rollers.

[0040] In the third step, the modified polyetheretherketone is prepared by the following steps:

[0041] Step S1, placing polyetheretherketone in a drying oven at 75°C for 24 hours, then adding it to dimethyl sulfoxide, magnetically stirring and adding sodium borohydride, heating to 100°C, magnetically stirring and reacting for 20 hours, filtering after the reaction, washing the filter cake with anhydrous ethanol, 10% by mass dilute hydrochloric acid and deionized water three times each, and then drying it at 80°C for 24 hours to obtain hydroxylated polyetheretherketone, and controlling the dosage ratio of polyetheretherketone, sodium borohydride and dimethyl sulfoxide to be 18g:6g:500mL;

[0042] Step S2, add the prepared hydroxylated polyetheretherketone to N,N-dimethylformamide, heat to 52°C, stir at a uniform speed for 20 hours, add silane-polyethylene glycol-carboxyl (Yusi Pharmaceutical), stir at a uniform speed and add N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine in sequence, heat to 72°C, stir at a uniform speed and react for 24 hours to obtain modified polyetheretherketone, and control the dosage ratio of hydroxylated polyetheretherketone, silane-polyethylene glycol-carboxyl, N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine and N,N-dimethylformamide to 2.2g:5g:9.25g:0.64g:50mL.

[0043] Example 3

[0044] A continuous production process for flat electromagnetic wires comprises the following steps:

[0045] The first step is to draw the copper wire and then roll it twice, and then use a sizing die to size it to obtain a processed conductor;

[0046] The second step is to process the processed conductor through NMT treatment (including alkali washing, acid washing, T liquid treatment, pure water ultrasonic cleaning, and drying, which can process nano-scale pits on the surface of the conductor to provide better adhesion for subsequent wrapping film sintering), and then anneal it in a nitrogen atmosphere to obtain an annealed conductor;

[0047] Step 3: Evenly mix the modified polyetheretherketone and polyphenylene sulfide in a weight ratio of 8:2, and make a wrapping film through a film-making machine, and then wrap it with a double-head wrapping machine after slitting;

[0048] The fourth step is to send the wrapped conductor into the sintering furnace through the guide wheel and sinter it at 380°C. During the sintering process, the wire is kept suspended. After sintering, it is sent to the hot pressing equipment through the guide wheel for hot pressing and shaping. Finally, it is cooled by air and then wound up to obtain the flat electromagnetic wire.

[0049] In the third step, the overlap rate is 55%, and the wrapping direction is S.

[0050] In the fourth step, hot pressing and shaping are completed by two groups of four mutually perpendicular rollers.

[0051] In the third step, the modified polyetheretherketone is prepared by the following steps:

[0052] Step S1, placing polyetheretherketone in a drying oven at 80°C for 24 hours, then adding it to dimethyl sulfoxide, stirring it magnetically and adding sodium borohydride, heating it to 110°C, stirring it magnetically and reacting it for 20 hours, filtering it after the reaction is completed, washing the filter cake with anhydrous ethanol, 10% dilute hydrochloric acid and deionized water three times respectively, and then drying it at 80°C for 24 hours to obtain hydroxylated polyetheretherketone, and controlling the dosage ratio of polyetheretherketone, sodium borohydride and dimethyl sulfoxide to be 18g:7g:500mL;

[0053] Step S2, add the prepared hydroxylated polyetheretherketone to N,N-dimethylformamide, heat to 55°C, stir at a uniform speed for 20 hours, add silane-polyethylene glycol-carboxyl (Yusi Pharmaceutical), stir at a uniform speed and add N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine in sequence, heat to 75°C, stir at a uniform speed and react for 24 hours to obtain modified polyetheretherketone, and control the dosage ratio of hydroxylated polyetheretherketone, silane-polyethylene glycol-carboxyl, N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine and N,N-dimethylformamide to 2.4g:5g:9.32g:0.66g:50mL.

[0054] Example 4

[0055] A continuous production process for flat electromagnetic wires comprises the following steps:

[0056] The first step is to draw the copper wire and then roll it twice, and then use a sizing die to size it to obtain a processed conductor;

[0057] The second step is to process the processed conductor through NMT treatment (including alkali washing, acid washing, T liquid treatment, pure water ultrasonic cleaning, and drying, which can process nano-scale pits on the surface of the conductor to provide better adhesion for subsequent wrapping film sintering), and then anneal it in a nitrogen atmosphere to obtain an annealed conductor;

[0058] Step 3: Evenly mix the modified polyetheretherketone and polyphenylene sulfide in a weight ratio of 8:2, and make a wrapping film through a film-making machine, and then wrap it with a double-head wrapping machine after slitting;

[0059] The fourth step is to send the wrapped conductor into the sintering furnace through the guide wheel and sinter it at 385°C. During the sintering process, the wire is kept suspended. After sintering, it is sent to the hot pressing equipment through the guide wheel for hot pressing and shaping. Finally, it is cooled by air and then wound up to obtain the flat electromagnetic wire.

[0060] In the third step, the overlap rate is 55%, and the wrapping direction is S.

[0061] In the fourth step, hot pressing and shaping are completed by two groups of four mutually perpendicular rollers.

[0062] In the third step, the modified polyetheretherketone is prepared by the following steps:

[0063] Step S1, placing polyetheretherketone in a drying oven at 85°C for 24 hours, then adding it to dimethyl sulfoxide, stirring it magnetically and adding sodium borohydride, heating it to 110°C, stirring it magnetically and reacting it for 20 hours, filtering it after the reaction is completed, washing the filter cake with anhydrous ethanol, 10% dilute hydrochloric acid and deionized water three times respectively, and then drying it at 80°C for 24 hours to obtain hydroxylated polyetheretherketone, and controlling the dosage ratio of polyetheretherketone, sodium borohydride and dimethyl sulfoxide to be 20g:8g:500mL;

[0064] Step S2, add the prepared hydroxylated polyetheretherketone to N,N-dimethylformamide, heat to 55°C, stir at a uniform speed for 20 hours, add silane-polyethylene glycol-carboxyl (Yusi Pharmaceutical), stir at a uniform speed and add N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine in sequence, heat to 75°C, stir at a uniform speed and react for 24 hours to obtain modified polyetheretherketone, and control the dosage ratio of hydroxylated polyetheretherketone, silane-polyethylene glycol-carboxyl, N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine and N,N-dimethylformamide to 2.5g:4-6g:9.36g:0.68g:50mL.

[0065] Comparative Example 1

[0066] Compared with Example 1, this comparative example uses commercially available polyetheretherketone instead of modified polyetheretherketone, and the rest is the same as Example 1.

[0067] The properties of the electromagnetic wires prepared in Examples 1 to 4 and Comparative Example 1 were tested, and the results are shown in Table 1 below:

[0068] Peeling performance: The electromagnetic wires prepared in Examples 1-4 were subjected to a stretching test after ring cutting to detect the length of stretching before peeling off from the conductor.

[0069] Table 1

[0070]

[0071] It can be seen from Table 1 above that the modified polyetheretherketone prepared in Examples 1-4 of the present invention maintains its excellent performance, and the room temperature breakdown test results all exceed the maximum test value of the test equipment 20kV. At the same time, the film cutting and tensile test shows that the modified polyetheretherketone has excellent conductor adhesion. After the film cutting and tensile test, the desorption length of the insulation layer of Examples 1-4 is within 2mm, while the insulation layer of the comparative example has been completely peeled off.

[0072] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field 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 concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A continuous production process for flat electromagnetic wire, characterized in that: The steps include: The first step is to draw the wire and then roll it twice, and then use a sizing die to size it to obtain a processed conductor; The second step is to subject the processed conductor to NMT treatment, and then anneal it in a nitrogen atmosphere to obtain an annealed conductor; Step 3: evenly mix the modified polyetheretherketone and polyphenylene sulfide in a weight ratio of 7-8:2-3, and then make a wrapping film through a film making machine, and then wrap it with a double-head wrapping machine after slitting; The fourth step is to send the wrapped conductor into a sintering furnace through a guide wheel for sintering. During the sintering process, the wire is kept suspended. After sintering, it is sent to a hot pressing device through a guide wheel for hot pressing and shaping. Finally, it is cooled by air and then taken up to obtain a flat electromagnetic wire. Modified polyetheretherketone is prepared by the following steps: Step S1, placing polyetheretherketone in a drying oven at 70-85°C for 24 hours, then adding it to dimethyl sulfoxide, stirring it magnetically and adding sodium borohydride, heating it to 100-110°C, stirring it magnetically and reacting it for 20 hours, filtering it after the reaction is completed, washing the filter cake with anhydrous ethanol, 10% dilute hydrochloric acid and deionized water three times respectively, and then drying it at 80°C for 24 hours to obtain hydroxylated polyetheretherketone; Step S2, adding the prepared hydroxylated polyetheretherketone to N,N-dimethylformamide, heating to 50-55°C, stirring at a constant speed for 20 hours, adding silane-polyethylene glycol-carboxyl, stirring at a constant speed and successively adding N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine, heating to 70-75°C, stirring at a constant speed and reacting for 24 hours to obtain modified polyetheretherketone.

2. A continuous production process for flat magnet wire according to claim 1, characterized in that: In the third step, the overlapping rate is 50%-55%, and the wrapping direction is S.

3. The continuous production process of flat electromagnetic wire according to claim 1, characterized in that: In the fourth step, hot pressing and shaping are completed by two groups of four mutually perpendicular rollers.

4. The continuous production process of flat electromagnetic wire according to claim 1, characterized in that: In step S1, the dosage ratio of polyetheretherketone, sodium borohydride and dimethyl sulfoxide is controlled to be (15-20 g): (5-8 g): 500 mL.

5. The continuous production process of flat electromagnetic wire according to claim 1, characterized in that: In step S2, the dosage ratio of hydroxylated polyetheretherketone, silane-polyethylene glycol-carboxyl, N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine and N,N-dimethylformamide is controlled to be (2-2.5g): (4-6g): (9.20-9.36g): (0.62-0.68g): 50mL.

Images