Method for cleaning spinneret plate through cooperation of abrasive particle flow and multi-frequency ultrasonic waves

Abstract

The invention discloses a method for cleaning a spinneret plate through cooperation of abrasive particle flow and multi-frequency ultrasonic waves. The method comprises the following steps: soaking a used spinneret plate in desalted water, drying, placing the spinneret plate on abrasive particle flow equipment, carrying out fluid grinding, soaking the spinneret plate in a hydrocarbon cleaning agent, airing, taking out, carrying out ultrasonic cleaning on the spinneret plate, and finally drying and purging. By means of the method, thousands of tiny holes and the surface of the spinneret plate can be safely and efficiently cleaned.

Description

Technical Field

[0001] The invention belongs to the field of spinneret cleaning methods and relates to a method for cleaning a spinneret by using abrasive flow in coordination with multi-frequency ultrasonic waves. Background Art

[0002] Polyacrylonitrile-based carbon fiber has the advantages of high specific strength, high specific modulus, high temperature resistance, corrosion resistance and good weaving performance. It is widely used in many fields such as sports equipment, construction engineering, oil extraction and aerospace. The production process of polyacrylonitrile-based carbon fiber includes spinning, pre-oxidation and carbonization, which involves a lot of equipment, including both textile equipment and high-temperature treatment equipment. The quality of spinning equipment is crucial to fiber quality, especially high-quality special fibers such as carbon fiber. One of the key components in the spinning equipment of polyacrylonitrile fiber is the spinneret. The spinneret is an alloy plate with a diameter of 5cm to 20cm and a thickness of only a few mm. There are one thousand to more than one hundred thousand spinnerets evenly arranged on it according to a certain distribution. The diameter of the spinneret ranges from 40 to 50 microns to 200 to 300 microns. Such a large number of densely distributed tiny spinnerets cannot be observed by the naked eye.

[0003] In the production of carbon fiber precursor, the cleanliness of the spinneret has a great impact on the quality of the product. Even very small impurities left in the spinneret hole will affect the quality of the finished precursor, which is most obvious in industrial-grade carbon fiber production. In all precursor production processes, polymer or organic impurities must be removed from the spinneret hole.

[0004] The currently commonly used method of cleaning the spinneret with an organic solvent has the disadvantages of long cleaning time, unclean cleaning, and high cost. Therefore, a new method of cleaning the spinneret is urgently needed to achieve cost reduction and efficiency improvement. Summary of the invention

[0005] The purpose of the present invention is to provide a method for cleaning a spinneret by using abrasive flow in conjunction with multi-frequency ultrasonic waves. The method combines abrasive flow spinneret with ultrasonic cleaning of the spinneret, thereby greatly reducing the time and cost of cleaning the spinneret.

[0006] The technical solution for achieving the purpose of the present invention is as follows:

[0007] A method for cleaning a spinneret by using abrasive flow in conjunction with multi-frequency ultrasonic waves comprises the following steps:

[0008] (1) Soaking the spinneret in desalted water to remove surface impurities and then drying;

[0009] (2) The dried spinneret is subjected to fluid grinding on a abrasive flow machining equipment. First, it is roughly ground with an oil-based abrasive with a particle size of 50 - 150 mesh, and then finely ground with an oil-based abrasive with a particle size of 200 - 600 mesh. The oil-based abrasive is composed of the following components by mass percentage: 52 - 57% of silicon carbide or alumina, 40 - 45% of industrial white oil, 1 - 3% of sodium stearate, and 1 - 3% of dimethyl silicone oil;

[0010] (3) The spinneret after fluid grinding is soaked in a hydrocarbon cleaning agent, taken out and naturally dried after removing the residual oil-based abrasive, and then placed in an ultrasonic cleaning equipment. Using demineralized water as the cleaning solution, the ultrasonic frequency is 100 - 250 KHz, the ultrasonic temperature is 30 - 60 °C, and the cleaning time is 1 - 5 h;

[0011] (4) The spinneret after ultrasonic cleaning is dried at 120 - 200 °C;

[0012] (5) The dried spinneret is purged with an air gun to remove dust.

[0013] Further, in step (1), the soaking time is 2 - 6 h.

[0014] Further, in step (2), the oil-based abrasive is composed of 40% industrial white oil, 2% sodium stearate, 1% dimethyl silicone oil, and 57% silicon carbide by mass fraction, or composed of 45% industrial white oil, 2% sodium stearate, 1% dimethyl silicone oil, and 52% alumina.

[0015] Further, in step (2), the extrusion pressure during fluid grinding is 1 MPa - 3 MPa.

[0016] Further, in step (2), the number of cycles of fluid squeezing one spinneret up and down is 3 - 50 times, the time for each fluid grinding is 1 - 4 min, and the total abrasive flow time is 3 - 200 min.

[0017] Further, in step (2), the spray flow rate of the fluid is 6 - 15 L / min.

[0018] Further, in step (3), the ultrasonic frequency is 25 - 275 KHz, and the number of ultrasonic emission devices is 1 - 4.

[0019] Further, in step (4), the drying time is 2 - 4 h.

[0020] Further, in step (5), the purging time is 1 - 3 min.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) The present invention uses silicon carbide or alumina as micro-powder, industrial white oil as the mineral oil raw material, sodium stearate as the lubricant, and dimethyl siloxane as the antioxidant to prepare an oil-based abrasive. During the fluid grinding process, it can effectively remove the dirt in the used spinneret and protect the spinneret, improving the cleaning effect.

[0023] (2) The present invention uses abrasive flow and ultrasonic cleaning to clean the spinneret. The entire cleaning process is simple and easy to operate, and the passing rate of the cleaned spinneret can be > 99%, greatly improving production stability.

[0024] (3) The present invention uses a method of synergistic cleaning of abrasive flow and multi-frequency ultrasound, which is applicable to spinnerets made of Hastelloy or higher hardness materials. Specific Embodiments

[0025] The present invention will be further described below in conjunction with specific embodiments.

[0026] Example 1

[0027] (1) Immerse the spinneret in deionized water for 2 h, remove the surface impurities and then dry it.

[0028] (2) Perform fluid grinding on the dried spinneret on an abrasive flow device. First, use an oil-based abrasive with a particle size of 120 mesh for rough grinding, the spraying flow rate is 8 L / min, and grind for 15 min; then use an oil-based abrasive with a particle size of 600 mesh for fine grinding, the spraying flow rate is 8 L / min, and grind for 15 min. The oil-based abrasive is composed of 40% industrial white oil, 2% sodium stearate, 1% dimethyl siloxane and 57% silicon carbide by mass fraction.

[0029] (3) Immerse the spinneret after fluid grinding in a hydrocarbon cleaning agent for 1 h, then take it out and let it dry naturally. Then place the spinneret in an ultrasonic cleaning device, use deionized water as the cleaning liquid, perform ultrasonic cleaning for 30 min, the ultrasonic temperature is 40 °C, and the frequencies of the three ultrasonic transmitters are 50 KHz, 75 KHz, and 100 KHz respectively.

[0030] (4) Dry the spinneret after ultrasonic cleaning at 150 °C for 2 h.

[0031] (5) Blow the dried spinneret with an air gun for 1 min to remove dust.

[0032] The passing rate of the cleaned spinneret was detected by a microscope. The result shows that the passing rate of the cleaned spinneret is 99.9%, and the total time from the use of the spinneret to the completion of cleaning is 7 - 8 h.

[0033] Example 2

[0034] This example is basically the same as Example 1, except that: the oil-based abrasive consists of 45% industrial white oil, 2% sodium stearate, 1% dimethyl silicone and 52% alumina by mass fraction.

[0035] The passing rate of the cleaned spinneret was detected by a microscope, and the result showed that the passing rate of the cleaned spinneret was 98.75%.

[0036] Comparative Example 1

[0037] (1) Place the spinneret in a heated dimethyl sulfoxide solution at a temperature of 100 °C and a boiling wash time of 18 h.

[0038] (2) Place the boiled spinneret in an ultrasonic cleaning device, use demineralized water as the cleaning liquid, ultrasonically clean for 1 h, the ultrasonic temperature is 45 °C, and the ultrasonic frequency is 50 KHz.

[0039] (3) Dry the ultrasonically cleaned spinneret at 150 °C for 2 h.

[0040] (4) Blow the dried spinneret with an air gun for 1 min to remove dust.

[0041] The passing rate of the cleaned spinneret was detected by a microscope, and the result showed that the passing rate of the cleaned spinneret was 96.485%, and the time consumed was about 20 h.

[0042] Comparative Example 2

[0043] This comparative example is basically the same as Example 1, except that in step (2), only abrasive with a particle size of 120 mesh is used for grinding.

[0044] The passing rate of the cleaned spinneret was detected by a microscope, and the result showed that the passing rate of the cleaned spinneret was 93.875%.

[0045] Comparative Example 3

[0046] This comparative example is basically the same as Example 1, except that in step (3), the ultrasonic temperature is 45 °C and the frequency of the ultrasonic emitter is 50 KHz.

[0047] The passing rate of the cleaned spinneret was detected by a microscope, and the result showed that the passing rate of the cleaned spinneret was 96.25%.

[0048] Comparative Example 4

[0049] This comparative example is basically the same as Example 1, except that silicon carbide is replaced by diamond.

[0050] The passing rate of the cleaned spinneret was detected by a microscope, and the result showed that the passing rate of the cleaned spinneret was 99.75%. However, after the spinneret was ground multiple times, scratches appeared at the orifice of the spinneret holes.

[0051] Comparative Example 5

[0052] This comparative example is substantially the same as Example 1, except that the oil-based abrasive is replaced with a water-based abrasive, and the water-based abrasive is composed of 45% water, 2% sodium polyacrylate (dispersant), and 53% silicon carbide by mass fraction.

[0053] The pass rate of the cleaned spinneret was tested by a microscope, and the result showed that the pass rate of the cleaned spinneret was 89.5%, with some individual hole blocking.

[0054] In summary, the method of the present invention for cleaning a spinneret by using abrasive flow in coordination with multi-frequency ultrasonic waves uses cheap abrasives, has a short cleaning time, and the final microscopic inspection pass rate can meet the conditions for spinning, which is economical and efficient.

Claims

1. A method for cleaning a spinneret by using abrasive flow and multi-frequency ultrasonic waves, characterized in that: The steps include: (1) Soak the spinneret in desalted water to remove surface impurities and then dry it; (2) subjecting the dried spinneret to fluid grinding on an abrasive flow device, firstly using an oil-based abrasive with a particle size of 50-150 meshes for coarse grinding, and then using an oil-based abrasive with a particle size of 200-600 meshes for fine grinding; the oil-based abrasive is composed of the following components by mass percentage: 52-57% of silicon carbide or aluminum oxide, 40-45% of industrial white oil, 1-3% of sodium stearate, and 1-3% of dimethylsiloxane; (3) Soak the spinneret after fluid grinding in a hydrocarbon cleaning agent to remove the residual oil-based abrasive, take it out and dry it naturally, and then place it in an ultrasonic cleaning device, using desalted water as the cleaning liquid, the ultrasonic frequency is 100~250KHz, the ultrasonic temperature is 30~60℃, and the cleaning time is 1~5h; (4) Drying the ultrasonically cleaned spinneret at 120-200°C; (5) Use an air gun to blow the dried spinneret to remove dust.

2. The method according to claim 1, characterized in that In step (1), the soaking time is 2 to 6 hours.

3. The method according to claim 1, characterized in that: In step (2), the oil-based abrasive is composed of 40% industrial white oil, 2% sodium stearate, 1% dimethyl siloxane and 57% silicon carbide, or 45% industrial white oil, 2% sodium stearate, 1% dimethyl siloxane and 52% aluminum oxide by mass fraction.

4. The method according to claim 1, characterized in that: In step (2), the extrusion pressure during fluid grinding is 1 MPa~3 MPa.

5. The method according to claim 1, characterized in that In step (2), the number of cycles of the fluid extruding a spinneret up and down is 3 to 50 times, the time of each fluid grinding is 1 to 4 minutes, and the total abrasive flow time is 3 to 200 minutes.

6. The method according to claim 1, characterized in that In step (2), the spray flow rate of the fluid is 6-15 L / min.

7. The method according to claim 1, characterized in that In step (3), the ultrasonic frequency is 25-275 kHz, and the number of ultrasonic emitting devices is 1-4.

8. The method according to claim 1, characterized in that In step (4), the drying time is 2 to 4 hours.

9. The method according to claim 1, characterized in that: In step (5), the purge time is 1 to 3 minutes.