Continuous spinning device for para-aramid fibers and control method

Abstract

The invention relates to a para-aramid fiber production process, in particular to a para-aramid fiber continuous spinning device and a control method. The device comprises a feeding assembly used for providing a polymer material; the mixing assembly is used for mixing the materials provided by the feeding assembly; the kneading machine is used for mixing the materials with concentrated sulfuric acid to form a spinning solution; the spinning machine is used for spinning the spinning solution to form nascent fibers, the washing machine is used for washing the nascent fibers, the drying machine is used for drying the washed nascent fibers to form finished fibers, and the controller is combined with a control method to control the running state of the spinning device. The feeding mode of the aramid fiber spinning technology is improved, continuous and stable spinning is achieved through combination of raw materials with different viscosities, the viscosity requirement of the spinning technology for polymerization raw materials is lowered, and decoupling of the polymerization technology and the spinning technology in an existing para-aramid fiber production technology is achieved.

Description

Technical Field

[0001] The invention relates to a para-aramid fiber production process, in particular to a para-aramid fiber continuous spinning device and a control method. Background Art

[0002] Para-aramid fiber, also known as poly(p-phenylene terephthalamide) fiber (hereinafter referred to as PPTA fiber), has excellent physical and chemical properties such as high strength, high modulus, high temperature resistance, acid and alkali resistance, and light weight. It is widely used in military fields such as aerospace and civilian fields. It is also widely used as a reinforcing material in composite materials.

[0003] The production process of para-aramid fiber mainly includes polymerization process and spinning process. The polymerization process mainly produces PPTA resin required for spinning. The spinning process dissolves PPTA resin in concentrated sulfuric acid to form PPTA / concentrated sulfuric acid liquid crystal slurry at high temperature (80-90°C). Under the action of relatively high shear force, the liquid crystal slurry is sprayed out at high speed in a dry spray manner. After water washing, drying and subsequent heat treatment, para-aramid fiber is obtained.

[0004] The strength of para-aramid fiber is the most important parameter of its product performance. According to the different strengths of the fiber, it is applied to different industrial fields. For example, the strength of para-aramid fiber in the civilian field is 20-23cN / dtex, and the strength of para-aramid fiber in the military field is generally required to be above 23cN / dtex. In addition, the consistency of para-aramid fiber strength is also an important parameter of para-aramid fiber, that is, the fluctuation range of para-aramid fiber strength within a certain length range is required to be as small as possible.

[0005] The strength of para-aramid fiber is mainly affected by two factors: polymer resin viscosity (or polymer molecular weight) and spinning environment. Among them, polymer resin viscosity is the main factor. Polymer resin viscosity is the macroscopic manifestation of polymer molecular weight. As the relative molecular mass increases, the strength and modulus of the fiber usually increase. This is because high molecular weight polymer chains are longer and the interaction between molecules is stronger, thereby improving the mechanical properties of the fiber. The spinning environment factor is a comprehensive factor, including the spinneret stretch ratio SSF and heat treatment process, among which the size of SSF affects the tensile flow orientation of the fiber, thereby affecting the strength of the fiber. The larger the SSF, the stronger the tensile flow orientation of the fiber and the higher the fiber strength. Heat treatment temperature, heat treatment tension, heat treatment time, etc. will affect the modulus and strength of the fiber.

[0006] At present, the continuous production of fixed-strength para-aramid fiber is a difficult problem in the industry. The reason is that the viscosity of the polymer resin cannot be controlled, while the spinning environment is relatively easy to control. Although the polymerization process is simple in principle, due to the high activity of the monomer, the reaction speed is very fast, and the solubility of PPTA in the solvent gradually decreases with the increase of molecular weight, so there are many factors affecting PPTA polymerization. The main influencing factors are: raw material purity, solvent system, moisture content, monomer ratio, monomer concentration, acid absorbent, reaction temperature and time, feeding method, stirring and shearing, etc.

[0007] The existing para-aramid fiber production process is as follows: PPTA resin is produced by polymerization process, PPTA resin is stored in tank area after testing, PPTA resin is transported from tank area to spinning workshop for spinning, strength test is performed after the finished fiber is obtained, finished fiber is classified according to the test results, and warehouse management personnel select products that meet the strength requirements for delivery according to sales orders. The existing production process has the following problems: 1. The problem of finished fiber inventory backlog. Due to the different viscosities of the polymer inventory materials, the finished fiber strengths produced after entering the spinning process are different, while the corresponding sales only require fibers within a specified strength range. This will lead to a large amount of finished fiber inventory, and it is necessary to wait for orders with different strength requirements to digest the inventory, thereby increasing production costs.

[0008] 2. The problem of polymer material inventory backlog. If polymers with corresponding viscosity are selected for spinning according to order requirements, para-aramid fibers that meet the strength requirements can be produced. However, as mentioned earlier, due to the uncertainty of the polymerization reaction, the viscosity of the polymer produced is also uncertain. If only polymers that meet the viscosity requirements are selected for spinning, a large amount of polymers with other viscosities will be accumulated, which will also lead to an increase in production costs. Summary of the invention

[0009] The object of the present invention is to provide a para-aramid fiber continuous spinning device and a control method to solve the problems raised in the above background technology.

[0010] The present invention provides a para-aramid fiber continuous spinning device, comprising: The feeding component is used to provide polymer materials that meet the spinning viscosity and quantity requirements. A mixing component is used to mix the materials provided by the feeding component. The kneading machine mixes the material provided by the mixing component with concentrated sulfuric acid to form a spinning solution, The spinneret spins the spinning solution to form primary fibers. Washing machine, for washing the raw fiber. The dryer dries the washed nascent fibers to form finished fibers. The controller controls the operation state of the spinning device in combination with the control method. The feed component includes a plurality of feed loops, which can provide polymer materials with different viscosities. The output ends of the feed loops are connected to the input ends of the mixing component, and the mixing component mixes the polymer materials with different viscosities inputted from the feed loops.

[0011] As a further embodiment of the present invention, a continuous spinning device for para-aramid fibers also includes a first pipeline and a second pipeline, wherein one end of the first pipeline and the second pipeline are respectively connected to the end of the feed loop, and the other end thereof is connected to the mixing assembly, and a control valve is provided between the feed loop and the first pipeline and the second pipeline for pipeline selection.

[0012] As a further embodiment of the present invention, the feed circuit comprises: Silos for storing polymer materials of different viscosities. A loss-in-weight scale is installed at the silo outlet to measure the output material flow. A pneumatic conveying device is connected to the loss-in-weight scale outlet and is used to convey polymer materials. The outlet of the pneumatic conveying device is connected to the first pipeline through a first valve, and the outlet of the pneumatic conveying device is connected to the second pipeline through a second valve.

[0013] As a further embodiment of the present invention, the mixing assembly includes a cyclone, a second feed pipe and a nozzle, a first feed pipe is provided on the outside of the cyclone, the first feed pipe is connected to the first pipeline, the nozzle is installed in the cyclone, and the nozzle is connected to the second pipeline through the second feed pipe.

[0014] As a further embodiment of the present invention, the upper part of the cyclone cylinder is a straight cylinder, a cover plate is provided on the top of the straight cylinder, the outer side of the straight cylinder is connected to the first feed pipe along the tangent direction, the bottom of the straight cylinder is connected to a conical barrel, the small end of the conical barrel faces downward, the lower end of the conical barrel is connected to a discharge port, and the discharge port is connected to the feed port of the kneading machine.

[0015] As a further embodiment of the present invention, an exhaust hole is further provided on the cover plate, and an air filter is provided at the outlet of the exhaust hole.

[0016] As a further embodiment of the present invention, the nozzle includes a nozzle body, which is a conical structure. A plurality of air channels are arranged in the nozzle body, wherein the air channel inlet is arranged on the conical bottom surface of the nozzle body, and the air channel outlet is arranged on the side of the nozzle body.

[0017] As a further embodiment of the present invention, the air passage is a spiral air passage, and a plurality of the air passages are arranged in a circular array along the central axis of the nozzle.

[0018] As a further embodiment of the present invention, the nozzle further includes a flow guide, which is a conical structure, and the bottom surface of the flow guide is installed at the center of the conical bottom surface of the nozzle body, for dispersing the airflow in the second feed pipe into multiple air channels.

[0019] As a further embodiment of the present invention, the spray head is rotatably mounted at the end of the second feed pipe.

[0020] As a further embodiment of the present invention, the mixing assembly also includes a bearing, which is installed on the outside of the end of the second feed pipe. A mounting portion is also provided above the bottom surface of the nozzle body, and the mounting portion is sleeved on the outer circle of the bearing and fixed by a flange.

[0021] As a further embodiment of the present invention, a disturbing body is provided on the inner wall of the conical barrel.

[0022] The present invention also provides a control method using the above-mentioned para-aramid continuous spinning device, the steps of which include: Step S1, obtain the viscosity data and inventory data of all polymer materials in the silo, sort them according to viscosity and store them in the dictionary D[k i ], where k i is the viscosity of the material in the silo, D[k i ] is the viscosity k i The stock value of the material; Step S2, obtaining the target fiber yield and the target fiber strength required to be produced by the spinning process, and obtaining the target viscosity η and the unit target mass M of the polymer material according to the target fiber yield and the target fiber strength requirements; Step S3, determine the dictionary D[k i ] whether there is k i =η, and the stock value D[k i ]>0, if the judgment result is true, execute step S5, otherwise execute step S4; Step S4, combining the polymer materials in the existing silo according to proportion and then unloading; Step S5, unloading.

[0023] The method of combining the polymer materials in step S4 is as follows: Step S41, obtain the dictionary D[k i ] The viscosity is greater than the target viscosity η and the first viscosity η1 with the largest stock value, and the silo with viscosity η1 is selected as the first silo; Step S42, obtain the dictionary D[k i ] The viscosity is less than the target viscosity η and the first viscosity η2 with the largest stock value, and the silo with viscosity η2 is selected as the second silo; Step S43, calculating the unit discharge volume of the first silo and the unit discharge volume of the second silo respectively by the following formulas: m1=(η-η2)M / (η1-η2); m2=(η1-η)M / (η1-η2); in, m1 is the unit discharge volume of the first silo; m2 is the unit discharge volume of the second silo.

[0024] As a further embodiment of the present invention, a control method for continuous spinning of para-aramid fiber is provided, wherein the unit discharge amount m1 of the first silo calculated in step S43 is compared with the unit discharge amount m2 of the second silo, and the polymer material corresponding to the maximum value of the two enters the mixer through the first feed pipe 217, and the polymer material corresponding to the minimum value enters the mixer through the second feed pipe.

[0025] Compared with the prior art, the present invention has the following beneficial effects: The present invention improves the feeding method of the aramid spinning process, realizes continuous and stable spinning by combining raw materials with different viscosities, reduces the viscosity requirements of the spinning process for the polymerization raw materials, and realizes the decoupling of the polymerization process and the spinning process in the existing para-aramid production process. In order to achieve the above technical effects, the present invention also provides a mixing device and a mixing method for users to mix materials with different viscosities, which can improve the mixing efficiency and mixing quality to ensure that the strength of the spinning product meets the requirements, and can reduce the inventory of the polymerization back end and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of a para-aramid fiber continuous spinning device of the present invention; Figure 2 for Figure 1 A cross-sectional view of the mixing assembly; Figure 3 for Figure 2 A magnified view of the part B in the middle; Figure 4 for Figure 2 Structural view of the middle cyclone; Figure 5 for Figure 2 Structural view of the middle nozzle; Figure 6 for Figure 2 Section view of AA in the middle; Figure 7 It is a flow chart of a method for controlling continuous spinning of para-aramid fibers according to the present invention; Figure 8 for Figure 7 The control flow of step S4; The meaning of each number in the figure is: Feeding assembly 1, mixing assembly 2, kneading machine 3, spinning machine 4, washing machine 5, drying machine 6, Feeding circuit 10, first pipeline 11, second pipeline 12, silo 101, loss-in-weight scale 102, pneumatic conveying device 103, first valve 104, second valve 105, Cyclone 21, second feed pipe 22, nozzle 23, bearing 24, flange 25, air filter 26, Conical barrel 211, straight barrel 212, feed port 213, cover plate 214, exhaust hole 215, mounting hole 216, first feed pipe 217, disruptor 218, The nozzle body 231 , the mounting portion 232 , the flow guide 233 , and the air channel 234 . DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0029] In the existing para-aramid production process, the strength of the spun products is uncertain, and the classification of the spun products is determined after the quality inspection of the finished fiber. Therefore, the existing continuous production of para-aramid is not truly continuous production. For example, if a customer requires the production of a batch of fibers with a strength of 21 cN / dtex, the existing production process is polymerization and spinning linkage production, and the quality inspectors will select the fibers that meet the required strength and provide them to the customers. Due to the uncertainty of the polymerization process, the viscosity of the polymer material is directly related to the strength of the finished fiber, so the strength of the spun product will also fluctuate. Therefore, the existing technical solution cannot continuously produce spun fibers of a certain strength. Example 1

[0030] like Figure 1As shown, the present invention provides a para-aramid fiber continuous spinning device, comprising: The feeding component 1 is used to provide polymer materials meeting the spinning viscosity and quantity requirements. The mixing component 2 mixes the materials provided by the feeding component 1. The kneading machine 3 mixes the material provided by the mixing component 2 with concentrated sulfuric acid to form a spinning solution. The spinneret 4 spins the spinning solution to form primary fibers. Washing machine 5, washing the raw fiber, The dryer 6 dries the washed nascent fibers to form finished fibers. The controller controls the operation state of the spinning device in combination with the control method. The feeding component 1 includes a plurality of feeding loops 10 , which can provide polymer materials with different viscosities. The output end of the feeding loop 10 is connected to the input end of the mixing component 2 , and the mixing component 2 mixes the polymer materials with different viscosities input by the feeding loop 10 .

[0031] In order to solve the problem that the prior art cannot continuously produce para-aramid fibers of a certain strength, a para-aramid continuous spinning device is provided in the present embodiment. The device decouples the existing polymerization process and the spinning process, and stores the polymer materials produced by the polymerization process in silos of different feeding loops 10 according to their different viscosities. The viscosity of the polymer materials can be determined by an online viscosity detection device at the end of the polymerization process, thereby improving the efficiency of manual detection.

[0032] In the technical solution provided in this embodiment, the controller can control the feeding component 1 to provide the polymer material required for spinning, including a single polymer material that meets the viscosity requirements or a combined polymer material that meets the viscosity requirements. When there is no material that meets the requirements in the stock polymer material, the controller can combine according to the viscosity of the existing materials. The combined materials cannot be directly put into the kneading machine 3 and mixed with concentrated sulfuric acid due to different viscosities, because the viscosity of materials with different viscosities combined with concentrated sulfuric acid is different, which will cause stratification and affect the spinning quality. Therefore, the mixing component 2 is required to fully mix the combined materials before putting them into the kneading machine 3. Example 2

[0033] like Figure 1 As shown, in addition to including all the contents of the previous embodiment, this embodiment further provides a feeding circuit 10, which includes: a silo 101 for storing polymer materials of different viscosities, a loss-in-weight scale 102 installed at the outlet of the silo 101 for measuring the output material flow rate, and a pneumatic conveying device 103 connected to the outlet of the loss-in-weight scale 102 for conveying polymer materials.

[0034] The feeding assembly 1 also includes a first pipeline 11 and a second pipeline 12, one end of the first pipeline 11 and the second pipeline 12 are respectively connected to the end of the feeding loop 10, and the other end thereof is connected to the mixing assembly 2, and a control valve is provided between the feeding loop 10 and the first pipeline 11 and the second pipeline 12 for pipeline selection.

[0035] The outlet of the pneumatic conveying device 103 is connected to the first pipeline 11 through a first valve 104 , and the outlet of the pneumatic conveying device 103 is connected to the second pipeline 12 through a second valve 105 .

[0036] In this embodiment, the controller can control the first valve 104 or the second valve 105 in different feeding loops 10 to operate and realize the connection with the first pipeline 11 or the second pipeline 12. In this embodiment, the first valve 104 or the second valve 105 adopts interlocking control to ensure that the silo 101 in each feeding loop 10 can only be connected to one of the first pipeline 11 or the second pipeline 12. By controlling the valve combination in each feeding loop 10, a combination of materials with different viscosities can be realized, that is, the selection of two materials with different viscosities and the control of their ratio can be realized. Example 3

[0037] like Figure 2-5 As shown, in addition to including all the contents of the previous embodiment, this embodiment further provides a mixing component 2, which includes a cyclone barrel 21, a second feed pipe 22 and a nozzle 23. A first feed pipe 217 is provided on the outside of the cyclone barrel 21, and the first feed pipe 217 is connected to the first pipeline 11. The nozzle 23 is installed in the cyclone barrel 21, and the nozzle 23 is connected to the second pipeline 12 through the second feed pipe 22.

[0038] Further, the upper part of the cyclone cylinder 21 is a straight cylinder 212, the top of the straight cylinder 212 is provided with a cover plate 214, the outer side of the straight cylinder 212 is connected to the first feed pipe 217 along the tangential direction, the bottom of the straight cylinder 212 is connected to the conical barrel 211, the small end of the conical barrel 211 is downward, the lower end of the conical barrel 211 is connected to the discharge port 213, and the discharge port 213 is connected to the feed port of the kneading machine 3. The cover plate 214 is also provided with an exhaust hole 215, and the outlet of the exhaust hole 215 is provided with an air filter 26. Preferably, the inner wall of the conical barrel 211 is provided with a turbulent body 218.

[0039] Further, the nozzle 23 includes a nozzle body 231, the nozzle body 231 is a conical structure, a plurality of air channels 234 are arranged in the nozzle body 231, the inlet of the air channel 234 is arranged at the conical bottom surface of the nozzle body 231, and the outlet thereof is arranged at the side of the nozzle body 231. Preferably, the air channel 234 is a spiral air channel, and the plurality of air channels 234 are arranged in a circular array along the central axis of the nozzle 23.

[0040] Furthermore, the nozzle 23 also includes a flow guide 233 , which is a conical structure. The bottom surface of the flow guide 233 is installed at the center of the conical bottom surface of the nozzle body 231 , and is used to disperse the airflow in the second feed pipe 22 into multiple air channels 234 .

[0041] Further, the nozzle 23 is rotatably mounted at the end of the second feed pipe 22. Preferably, the mixing assembly 2 further includes a bearing 24, which is mounted on the outer side of the end of the second feed pipe 22, and a mounting portion 232 is further provided above the bottom surface of the nozzle body 231, and the mounting portion 232 is sleeved on the outer circle of the bearing 24 and fixed by a flange 25.

[0042] In this embodiment, a mixing method is provided, where two materials of different viscosities enter the mixing assembly through different channels. The two materials of different viscosities are combined in a certain proportion. When the flow rates of the two materials are different, the material with a larger flow rate enters the cyclone 21 through the first feed pipe 217, and the material with a smaller flow rate enters the nozzle 23 through the second feed pipe 22.

[0043] One type of material enters the cyclone 21 driven by the high-pressure airflow and spirals down along the inner wall of the conical barrel 211, and another type of material enters the cyclone 21 through the spiral air passage 234 of the nozzle 23. The rotation direction of the material entering the cyclone 21 through the first feed pipe 217 is opposite to the rotation direction of the material entering the cyclone 21 through the nozzle 23. Figure 6 As shown, from a top view, the material entering the cyclone 21 through the first feed pipe 217 rotates counterclockwise, and the spiral direction of the air channel 234 is clockwise, so when the two materials come into contact in the cylinder, the mixing effect is better due to the opposite directions. Furthermore, since the inner wall is provided with a turbulent body 218, when the material spirally descending along the wall passes through the turbulent body 218, the turbulent body 218 will change the flow direction of the material and throw it to a position close to the nozzle 23, so that the two materials are mixed in the air, thereby improving the mixing effect.

[0044] In this embodiment, the nozzle 23 is further rotatably mounted at the lower end of the second feed pipe 22, and the rotation of the nozzle 23 is achieved by the spiral airflow in the air channel 234. The advantage of this design is that the rotating nozzle 23 is conducive to the mixing of the two materials, avoiding uneven mixing caused by long-term uneven flux of materials in multiple air channels 234 in the nozzle 23. Example 4

[0045] like Figure 7 As shown, the present invention also provides a control method using the above-mentioned para-aramid continuous spinning device, the steps of which include: Step S1, obtain the viscosity data and inventory data of all polymer materials in the silo, sort them according to viscosity and store them in the dictionary D[k i ], where k i is the viscosity of the material in the silo, D[k i ] is the viscosity k i The stock value of the material; Step S2, obtaining the target fiber yield and the target fiber strength required to be produced by the spinning process, and obtaining the target viscosity η and the unit target mass M of the polymer material according to the target fiber yield and the target fiber strength requirements; Step S3, determine the dictionary D[k i ] whether there is k i =η, and the stock value D[k i ]>0, if the judgment result is true, execute step S5, otherwise execute step S4; Step S4, combining the polymer materials in the existing silo according to proportion and then unloading; Step S5, unloading.

[0046] like Figure 8 As shown, the method of combining the polymer materials in step S4 is as follows: Step S41, obtain the dictionary D[k i ] The viscosity is greater than the target viscosity η and the first viscosity η1 with the largest stock value, and the silo with viscosity η1 is selected as the first silo; Step S42, obtain the dictionary D[k i ] The first viscosity η2 with a viscosity less than the target viscosity η and a maximum stock value is selected, and the silo with a viscosity of η2 is selected as the second silo; Step S43, calculating the unit discharge volume of the first silo and the unit discharge volume of the second silo respectively by the following formulas: m1=(η-η2)M / (η1-η2); m2=(η1-η)M / (η1-η2); in, m1 is the unit discharge volume of the first silo; m2 is the unit discharge volume of the second silo.

[0047] As a further embodiment of the present invention, a control method for continuous spinning of para-aramid fiber is provided, wherein the unit discharge amount m1 of the first silo calculated in step S43 is compared with the unit discharge amount m2 of the second silo, and the polymer material corresponding to the maximum value of the two enters the mixer through the first feed pipe 217, and the polymer material corresponding to the minimum value enters the mixer through the second feed pipe (22).

[0048] This embodiment provides a method for mixing polymer materials. The advantage of this method is that it maximizes the use of the material with the largest inventory among the current polymer materials, reduces the extrusion of the polymer materials and reduces production costs. At the same time, the selection of the polymer material with the largest inventory is conducive to the stability of spinning quality.

[0049] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A para-aramid fiber continuous spinning device, comprising: The material supply component (1) is used to provide polymer material meeting the spinning viscosity and quantity requirements. A mixing component (2) is used to mix the materials provided by the feeding component (1). The kneading machine (3) mixes the material provided by the mixing component (2) with concentrated sulfuric acid to form a spinning solution. The spinneret (4) spins the spinning solution to form primary fibers. The washing machine (5) washes the raw fibers. The dryer (6) dries the washed nascent fibers to form finished fibers. The controller controls the operation state of the spinning device in combination with the control method. It is characterized in that the feeding component (1) comprises a plurality of feeding loops (10), and the plurality of feeding loops (10) can provide polymer materials with different viscosities, the output end of the feeding loop (10) is connected to the input end of the mixing component (2), and the mixing component (2) mixes the polymer materials with different viscosities input by the feeding loop (10).

2. The para-aramid fiber continuous spinning device according to claim 1, characterized in that: The invention also comprises a first pipeline (11) and a second pipeline (12), wherein one end of the first pipeline (11) and the second pipeline (12) are respectively connected to the end of the feed loop (10), and the other end thereof is connected to the mixing assembly (2), and a control valve is provided between the feed loop (10) and the first pipeline (11) and the second pipeline (12) for pipeline selection.

3. The para-aramid fiber continuous spinning device according to claim 2, characterized in that: The feed circuit (10) comprises: The silo (101) is used to store polymer materials of different viscosities. A loss-in-weight scale (102) is installed at the outlet of the silo (101) to measure the output material flow rate. A pneumatic conveying device (103) is connected to the outlet of the loss-in-weight scale (102) and is used to convey polymer materials. The outlet of the pneumatic conveying device (103) is connected to the first pipeline (11) through a first valve (104), and the outlet of the pneumatic conveying device (103) is connected to the second pipeline (12) through a second valve (105).

4. The para-aramid fiber continuous spinning device according to claim 3, characterized in that: The mixing assembly (2) comprises a cyclone (21), a second feed pipe (22) and a nozzle (23). A first feed pipe (217) is provided outside the cyclone (21), and the first feed pipe (217) is connected to the first pipeline (11). The nozzle (23) is installed in the cyclone barrel (21), and the nozzle (23) is connected to the second pipeline (12) through the second feed pipe (22).

5. The para-aramid fiber continuous spinning device according to claim 4, characterized in that: The upper part of the cyclone cylinder (21) is a straight cylinder (212), the top of the straight cylinder (212) is provided with a cover plate (214), the outer side of the straight cylinder (212) is connected to the first feed pipe (217) along the tangent direction, the bottom of the straight cylinder (212) is connected to a conical barrel (211), the small end of the conical barrel (211) faces downward, the lower end of the conical barrel (211) is connected to a discharge port (213), and the discharge port (213) is connected to a feed port of the kneading machine (3).

6. The para-aramid fiber continuous spinning device according to claim 5, characterized in that: The cover plate (214) is also provided with an exhaust hole (215), and an outlet of the exhaust hole (215) is provided with an air filter (26).

7. The para-aramid fiber continuous spinning device according to claim 6, characterized in that: The nozzle (23) comprises a nozzle body (231), the nozzle body (231) is a conical structure, a plurality of air channels (234) are arranged in the nozzle body (231), the inlet of the air channel (234) is arranged on the conical bottom surface of the nozzle body (231), and the outlet thereof is arranged on the side of the nozzle body (231).

8. The para-aramid fiber continuous spinning device according to claim 7, characterized in that: The air passage (234) is a spiral air passage, and a plurality of the air passages (234) are arranged in a circular array along the central axis of the nozzle (23).

9. The para-aramid fiber continuous spinning device according to claim 8, characterized in that: The nozzle (23) further comprises a flow guide (233), the flow guide (233) being a conical structure, the bottom surface of the flow guide (233) being installed at the center of the conical bottom surface of the nozzle body (231), and being used for dispersing the airflow in the second feed pipe (22) into a plurality of air passages (234).

10. The para-aramid fiber continuous spinning device according to claim 9, characterized in that: The nozzle (23) is rotatably mounted at the end of the second feeding pipe (22).

11. The para-aramid fiber continuous spinning device according to claim 10, characterized in that: The mixing assembly (2) further comprises a bearing (24), wherein the bearing (24) is mounted on the outer side of the end of the second feed pipe (22), and a mounting portion (232) is further provided above the bottom surface of the nozzle body (231), wherein the mounting portion (232) is sleeved on the outer circle of the bearing (24) and fixed by a flange (25).

12. The para-aramid fiber continuous spinning device according to claim 11, characterized in that: The inner wall of the conical barrel (211) is provided with a disturbing body (218).

13. A method for controlling continuous spinning of para-aramid fiber, using the para-aramid fiber continuous spinning device according to any one of claims 1 to 11, comprising the steps of: Step S1, obtain the viscosity data and inventory data of all polymer materials in the silo, sort them according to viscosity and store them in the dictionary D[k i ], where k i is the viscosity of the material in the silo, D[k i ] is the viscosity k i The stock value of the material; Step S2, obtaining the target fiber yield and the target fiber strength required to be produced by the spinning process, and obtaining the target viscosity η and the unit target mass M of the polymer material according to the target fiber yield and the target fiber strength requirements; Step S3, determine the dictionary D[k i ] whether there is k i =η, and the stock value D[k i ]>0, if the judgment result is true, execute step S5, otherwise execute step S4; Step S4, combining the polymer materials in the existing silo according to proportion and then unloading; Step S5, unloading.

14. The control method for continuous spinning of para-aramid fiber according to claim 13, characterized in that: The method for combining the polymer materials in step S4 is as follows: Step S41, obtain the dictionary D[k i ] The viscosity is greater than the target viscosity η and the first viscosity η1 with the largest stock value, and the silo with viscosity η1 is selected as the first silo; Step S42, obtain the dictionary D[k i ] The first viscosity η2 with a viscosity less than the target viscosity η and a maximum stock value is selected, and the silo with a viscosity of η2 is selected as the second silo; Step S43, calculating the unit discharge volume of the first silo and the unit discharge volume of the second silo respectively by the following formulas: m1=(η-η2)M / (η1-η2); m2=(η1-η)M / (η1-η2); in, m1 is the unit discharge volume of the first silo; m2 is the unit discharge volume of the second silo.

15. The control method for continuous spinning of para-aramid fiber according to claim 14, characterized in that: The unit discharge amount m1 of the first silo calculated in step S43 is compared with the unit discharge amount m2 of the second silo, and the polymer material corresponding to the maximum value between the two enters the mixer through the first feed pipe 217, and the polymer material corresponding to the minimum value enters the mixer through the second feed pipe (22).

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