A method for efficiently and continuously producing para-aramid pulp

Abstract

The application discloses a kind of high-efficiency continuous production p-aramid pulp methods, comprising the following steps: surface modification is carried out to filament fiber;Continuous feeding into pulp: filament fiber is cut into short-cut fiber, then through double helix mixer, water is added simultaneously, mixed stirring and transportation are carried out, and short-cut fiber solution of required concentration is configured;Two-stage refining treatment: aramid pulp in short-cut fiber solution reaches required length by sequentially passing through primary refining system and secondary refining system;Primary refining system and secondary refining system are all formed by multiple high-shear dispersion machines in series, and the rotating speed of high-shear dispersion machine in secondary refining system is higher than that of high-shear dispersion machine in primary refining system;After filtration, dry opening treatment is carried out, and p-aramid pulp finished product is obtained.The method has obvious advantages in improving production efficiency, reducing production cost, stabilizing output, improving product quality and environmental protection benefits compared with prior art.

Description

Technical Field

[0001] This invention relates to the field of fiber preparation technology, and more specifically, to a method for efficient and continuous production of para-aramid pulp. Background Technology

[0002] In the production of para-aramid pulp, the traditional intermittent spinning and cutting method is the main preparation method. This method utilizes the characteristic that the rigid, straight-chain macromolecular structure of para-aramid readily undergoes longitudinal fibrillation. Para-aramid filaments are cut into short fibers, which are then mechanically beaten and pulped in water to achieve fibrillation. However, this traditional method has a series of problems and drawbacks, limiting its application in industrial production.

[0003] First, intermittent production typically leads to lower production efficiency. The downtime and start-up periods during the production cycle waste resources and labor, preventing the maximization of efficiency. Second, the frequent switching between shutdowns and starts requires more energy and labor, increasing production costs and hindering efficiency improvements. Third, intermittent production often results in fluctuating production volumes, making it difficult to meet market demand, especially in industries with highly volatile demand, leading to unstable output. Furthermore, equipment that is frequently started and stopped wears out more easily, requiring more frequent equipment maintenance and repairs, increasing production costs. Intermittent production can result in high levels of semi-finished and finished goods inventory, tying up significant capital and potentially leading to obsolescence or obsolescence, causing inventory management problems. The difficulty in implementing precise control is another issue; the discontinuous nature of the production process makes precise process control and optimization challenging, potentially affecting product quality and consistency. Frequent shutdowns and starts can lead to unnecessary energy waste and negatively impact the environment.

[0004] Although existing technologies have proposed some methods for continuous production of para-aramid pulp (such as CN104594094A "A method for continuous production of para-aramid pulp"), there are still some shortcomings, such as a relatively complicated process flow, long grinding time and poor effect, unstable finished product quality, and poor uniformity.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a method for efficient and continuous production of para-aramid pulp. This method solves the problems of low efficiency, high cost, and unstable output in traditional para-aramid pulp production methods, and provides an innovative solution for the industrial production of para-aramid pulp.

[0007] This invention is implemented as follows:

[0008] This invention provides a method for efficient and continuous production of para-aramid pulp, comprising the following steps: surface modification of filament fibers;

[0009] Continuous feeding: Long filament fibers are cut into short fibers, and then water is added, mixed and stirred and transported simultaneously through a double spiral mixer to prepare a short fiber solution of the required concentration;

[0010] Two-stage pulping process: The aramid pulp in the short-cut fiber solution is passed through a primary pulping system and a secondary pulping system in sequence to achieve the required length; both the primary and secondary pulping systems are composed of multiple high-shear dispersers connected in series, and the rotational speed of the high-shear dispersers in the secondary pulping system is higher than that of the high-shear dispersers in the primary pulping system.

[0011] After filtration, the pulp is dried and loosened to obtain the finished para-aramid pulp.

[0012] Compared to existing technologies, the continuous feeding step of this invention achieves simultaneous mixing and conveying, significantly saving time and improving production efficiency, enabling continuous production throughout the entire process. The two-stage refining system effectively prevents material from repeatedly entering the same refining vessel, solving the problem of inconsistent material lengths in intermittent production. The series connection of multiple high-shear dispersers in each refining system allows the aramid pulp to gradually reach the required length during multiple refining processes, while significantly reducing refining time compared to existing steps, effectively improving refining efficiency. In summary, the efficient continuous production method for para-aramid pulp of this invention maximizes production efficiency while reducing energy consumption and labor requirements, thereby lowering production costs and facilitating large-scale application in the production of para-aramid pulp.

[0013] In an optional embodiment, the chopped fiber solution further includes the following steps before entering the primary refining system: stirring in a buffer tank; and maintaining a constant liquid level in the buffer tank by adjusting the inlet and outlet flow rates. By maintaining a constant liquid level in the buffer tank, it can be ensured that the aramid fiber slurry can quickly enter the refining stage after mixing in the twin-helix mixer, achieving true continuous production.

[0014] In an optional implementation, when the chopped fiber solution enters the buffer tank, the primary refining system is first started. When the speed of the high-shear disperser in the primary refining system reaches the set value, the buffer tank can continuously feed material into the primary refining system.

[0015] In an optional embodiment, both the primary and secondary refining systems are equipped with 4 to 6 high-shear dispersers connected in series. This arrangement prevents material from repeatedly entering the same refining vessel, ensuring that the material remains in each high-shear disperser for a shorter time, effectively guaranteeing cutting speed and accuracy, and significantly reducing the total time consumed in the refining process. Preferably, each stage of the refining system consists of five high-shear dispersers connected in series.

[0016] In an optional embodiment, the high-shear disperser in the primary refining system rotates at a speed of 35–45 r / min, and the high-shear disperser in the secondary refining system rotates at a speed of 40–60 r / min. The higher speed of the high-shear disperser in the secondary refining system compared to the primary system results in more uniform pulp length and improved refining efficiency.

[0017] Preferably, the total refining time for the primary refining system is 30 minutes, and the total refining time for the secondary refining system is 40 minutes. The fiber length obtained after refining in the secondary refining system for the above-mentioned durations will meet the standard.

[0018] In an optional embodiment, the double-helix mixer is equipped with a water inlet; the concentration of the chopped fiber solution prepared by the double-helix mixer is 2-4%. In traditional production processes, the double-helix mixer is only used for material transport. However, this invention, by incorporating a water inlet into the double-helix mixer, allows for simultaneous water mixing during transport, preparing a chopped fiber solution with a concentration of 2-4%. This combines the transport and solution preparation processes into one, shortening the feeding and pulping steps, effectively reducing energy consumption. Furthermore, the double-helix mixer does not need to be shut down during solution preparation, truly enabling efficient and continuous production of aramid pulp. Preferably, the concentration of the chopped fiber solution is 3%.

[0019] In an optional implementation, the drying and opening process is carried out using an integrated drying and opening machine. The processing temperature is 105–125°C, the power is 0.3–0.6 MPa, the processing time is 15–30 min, and the rotation speed is 110–130 r / min. By combining the drying and opening steps into one integrated machine, production efficiency is maximized while reducing energy consumption and labor requirements, thereby lowering production costs.

[0020] In an optional embodiment, the surface modifier used in the surface modification step is polyethylene glycol ester (PEG). By immersing the filament fibers in PEG to modify their surface, the dispersion properties and antistatic properties of the filaments can be effectively improved, resulting in more uniform fibrillation in subsequent processes. PEG can also improve the smoothness of aramid fibers, maintain a stable coefficient of friction, reduce static electricity generation during fiber production, and give the aramid fibers better bundle-like properties.

[0021] In an optional embodiment, the length of the chopped fibers is 3-6 mm, and the length of the aramid pulp in the slurry after two-stage refining is 0.8-0.97 mm. The aramid pulp obtained by the method of the present invention has a more uniform length and meets the required dimensions.

[0022] In an optional embodiment, the filtration step employs a belt filter with a filtration pressure of 0.4–0.8 MPa and a filtration flow rate of 190–220 kg / h. Through the above filtration steps, aramid pulp lumps can be obtained.

[0023] The present invention has the following beneficial effects:

[0024] (1) Improve production efficiency: The continuous production method avoids the frequent shutdowns and restarts in traditional intermittent production, reduces ineffective production time, and thus improves production efficiency.

[0025] (2) Reduce production costs: By reducing the number of equipment start-ups and shutdowns in each process, reducing energy consumption, and reducing labor demand, production costs have been effectively reduced and production efficiency has been improved.

[0026] (3) Stable output: Through the multi-stage series pulping system and the integrated opening and drying, continuous production of para-aramid pulp is achieved, avoiding the problem of output fluctuation in the traditional production method and ensuring stable product output.

[0027] (4) Improve product quality: By adopting technologies such as filament surface modification and multi-stage pulping system, the fiber dispersion and fibrillation process are optimized, resulting in more uniform length of the final product and improved product quality and consistency.

[0028] (5) Environmental benefits: Through the optimization of the process flow, energy waste is reduced and the negative impact of frequent shutdowns and restarts on the environment is avoided, which has certain environmental benefits.

[0029] (6) Refined control adopts a multi-stage grinding system and an integrated design of opening and drying, which realizes more refined production control and improves the precise control of product quality.

[0030] In summary, the method for efficient and continuous production of para-aramid pulp provided by this invention has significant advantages over existing technologies in terms of improving production efficiency, reducing production costs, stabilizing output, improving product quality, and environmental benefits. It provides a more advanced, economical, and environmentally friendly solution for the production of para-aramid pulp. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic flowchart of a method for continuous production of para-aramid pulp according to some embodiments of the present invention.

[0033] Figure 2 Scanning electron microscope image of the finished aramid pulp obtained in Example 1 of this invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0035] The method for efficient and continuous production of para-aramid pulp provided by the present invention will be described in detail below.

[0036] This invention provides a method for efficient and continuous production of para-aramid pulp, comprising at least the following steps:

[0037] Surface modification of filament fibers;

[0038] Continuous feeding: Long filament fibers are cut into short fibers, and then water is added, mixed and stirred and transported simultaneously through a double spiral mixer to prepare a short fiber solution of the required concentration;

[0039] Two-stage pulping process: The aramid pulp in the short fiber solution is passed through a primary pulping system and a secondary pulping system in sequence to achieve the required length; both the primary and secondary pulping systems are composed of multiple high-shear dispersers connected in series, and the high-shear dispersers in the secondary pulping system have a higher rotational speed than the high-shear dispersers in the primary pulping system.

[0040] After filtration, the pulp is dried and loosened to obtain the finished para-aramid pulp.

[0041] In the above process steps, the continuous feeding step enables simultaneous mixing and conveying, significantly saving time and improving production efficiency, thus achieving continuous production throughout the entire process. The two-stage refining system effectively prevents material from repeatedly entering the same refining vessel, solving the problem of varying material lengths in intermittent production. The design of multiple high-shear dispersers connected in series in each refining system allows the aramid pulp to gradually reach the required length during multiple refining processes, while significantly reducing refining time compared to existing refining steps, effectively improving refining efficiency.

[0042] For reference, the chopped fiber solution also includes the following steps before entering the primary refining system: stirring in a buffer tank; and maintaining a constant liquid level in the buffer tank by adjusting the inlet and outlet flow rates. By maintaining a constant liquid level in the buffer tank, it can be ensured that the aramid fiber slurry can quickly enter the refining stage after mixing in the twin-helix mixer, achieving true continuous production. The rotation speed of the stirring paddle in the buffer tank is 20–40 r / min.

[0043] For reference, when the chopped fiber solution enters the buffer tank, the primary refining system is started first. Once the high-shear disperser in the primary refining system reaches the set speed, the buffer tank can continuously feed material into the primary refining system. The buffer tank can accumulate the minimum amount of pulp required for the primary refining system before the speed of the primary refining system stabilizes. This process is very short, ensuring that each batch of pulp entering the two-stage refining system has a stable refining effect and maintains uniform quality and dimensions. However, if the pulp enters the refining system directly without passing through the buffer tank, the length of the resulting pulp will be longer during the initial period before the refining system speed reaches the set value.

[0044] In a preferred embodiment, both the primary and secondary refining systems are equipped with 4 to 6 high-shear dispersers connected in series. This arrangement avoids repeated material entry into the same refining vessel and ensures that the material remains in each high-shear disperser for a shorter time, effectively ensuring cutting speed and accuracy, and significantly reducing the total refining process time. Too few high-shear dispersers in each refining system will result in insufficient refining effect, while too many will lead to excessive energy consumption and a smaller marginal gain in refining effect. In a preferred embodiment, each refining system consists of five high-shear dispersers connected in series.

[0045] For reference, the high-shear disperser speed in the primary refining system is 35–45 r / min, and the high-shear disperser speed in the secondary refining system is 40–60 r / min. The higher speed of the high-shear disperser in the secondary refining system compared to the primary system results in more uniform pulp length and improved refining efficiency. The rotational speed of the high-shear disperser in the primary refining system is adjusted within the range of 35–45 r / min, while the rotational speed of the high-shear disperser in the secondary refining system is adjusted within the range of 40–60 r / min. For example, the rotational speeds of the high-shear dispersers in the two systems can be set to 35 r / min and 40 r / min, or 40 r / min and 45 r / min, or 45 r / min and 50 r / min, or 40 r / min and 60 r / min, or 45 r / min and 55 r / min, or 45 r / min and 60 r / min, or 38 r / min and 52 r / min, etc. Adjustments can be made within these parameter ranges according to actual needs, ensuring that the rotational speed of the high-shear disperser in the secondary refining system is higher than that in the primary refining system. Preferably, in the specific production process, when the mixed solution is fed into the pre-grinding mill, the high-shear disperser is started in advance to reach a rotational speed of 35–45 r / min. The material then passes through five high-shear dispersers connected in series for the first stage of refining. The pre-grinding mill supplies material at a constant rate at both its inlet and outlet, ensuring a constant liquid level and a consistent amount of aramid pulp passing through the high-shear disperser per unit time. This results in pulp of as uniform length as possible after cutting. The material from the primary grinding stage continuously enters the secondary grinding system, which also consists of five interconnected high-shear dispersers connected in series. The material delivery speed is consistent with the primary grinding system, and the secondary high-shear dispersers operate at 40–60 r / min, further increasing their cutting speed and precision.

[0046] For reference, the total refining time for the primary refining system is 30 minutes, and the total refining time for the secondary refining system is 40 minutes. After primary refining, the length of the chopped fibers is 2-3 mm, and after secondary refining, the length of the chopped fibers is 0.8 mm, which meets the size standard of aramid pulp finished product.

[0047] For reference, the double-helix mixer is equipped with a water inlet; the concentration of the chopped fiber solution prepared by the double-helix mixer is 2-4%. In traditional production processes, the double-helix mixer is only used for transporting materials, while the double-helix mixer of this invention is equipped with a water inlet, allowing for simultaneous water addition and mixing of materials during transport. The rotation of the double-helix mixer is used to mix and stir the raw materials, causing the chopped fibers to loosen and fully disperse in the water. By controlling the raw material flow rate and stirring power rate, the short fibers can be prepared into a chopped fiber solution of the required concentration (preferably 3%), realizing simultaneous mixing and transportation. This combines the two processes of transportation and preparation of the chopped fiber solution into one, saving time, improving production efficiency, and truly achieving continuous production throughout the entire process. In a preferred embodiment, the water flow rate in the water inlet can be controlled at 180-200 kg / h. The chopped fiber feeding rate is mainly determined by the filament cutting rate, with the filament winding rate being 50 m / min.

[0048] For reference, the drying and opening process is carried out using an integrated drying and opening machine. The processing temperature is 120℃, the power is 0.5 MPa, the processing time is 15–30 min, and the rotation speed is 110–130 r / min. By combining the drying and opening steps into one integrated machine, production efficiency is maximized while reducing energy consumption and labor requirements, thereby lowering production costs.

[0049] For reference, the surface modifier used in the surface modification step is polyethylene glycol ester (PEG) of fatty acids. By immersing the filament fibers in PEG of fatty acids for surface modification, the dispersion properties and antistatic properties of the filaments can be effectively improved, resulting in more uniform fibrillation in subsequent processes. PEG of fatty acids can also improve the smoothness of aramid fibers, maintain a stable coefficient of friction, reduce static electricity generation during fiber production, and give the aramid fibers better bundle-like properties.

[0050] For reference, the length of the chopped fibers formed after cutting the filament fibers is 6mm, which is shorter than the chopped fibers used in previous production, making it more conducive to the rapid swelling and dispersion of the fibers in water. After two-stage pulping, the length of the aramid pulp in the slurry is 0.8-0.97mm, which meets the finished product size requirements, and the length of the aramid pulp is more uniform.

[0051] For reference, the filtration step typically uses a belt filter with a filtration pressure of 0.4–0.8 MPa and a filtration flow rate of 190–220 kg / h. After filtering out the solvent through the above filtration steps, aramid pulp lumps can be obtained.

[0052] For reference, aramid pulp that has been dried and opened can be used to obtain finished aramid pulp through an automatic weighing and packaging system.

[0053] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0054] Example 1

[0055] Please see Figure 1 This embodiment provides a method for efficient and continuous production of para-aramid pulp, comprising the following steps:

[0056] (1) The aramid filament fiber is unwound and bundled to make the filament fiber aggregate. It is then immersed in an aqueous solution (concentration of 3%) containing the surface modifier fatty acid polyethylene glycol ester, so that the surface of the filament fiber is coated with the surface modifier fatty acid polyethylene glycol ester. Then, it is conveyed to the filament cutting machine through the drawing roller and cut into 6mm short fibers.

[0057] (2) Add chopped fibers to the double-helix mixer. Add water during the conveying process, mixing and conveying simultaneously to loosen the chopped fibers and fully disperse them in the water. Control the chopped fiber feed rate and the total denier of the filaments in step (1) to control the concentration of the chopped fiber solution, thereby preparing a 3% chopped fiber solution. The water flow rate is 180 kg / h. The mixed slurry enters a buffer tank with a stirring function, and the high-shear disperser in the primary grinding system is turned on in advance to reach a speed of 33 r / min. The inlet and outlet of the buffer tank are always kept open. The liquid level in the tank is kept constant by adjusting the inlet and outlet flow rates to ensure that the aramid fiber slurry can quickly enter the grinding stage after mixing in the double-helix mixer. The stirring speed of the buffer tank is 33 r / min, and the temperature inside the tank is 20-25℃.

[0058] (3) The mixed solution is fed into the primary refining system at a feed rate of 190 kg / h, passing through five high-shear dispersers connected in series for the first stage of refining. After 30 minutes of initial refining, the material continuously enters the secondary refining system, which also consists of five interconnected high-shear dispersers connected in series. The material conveying speed is consistent with that of the primary refining system. The high-shear dispersers in the secondary refining system rotate at 52 r / min for 40 minutes to further increase their cutting speed and precision. After multi-stage refining, the aramid pulp is shredded to approximately 0.8 mm, meeting the length requirements of the finished product.

[0059] (4) The solvent is filtered out by a belt filter at a pressure of 0.6 MPa and a flow rate of 190 kg / h to obtain aramid pulp blocks. Then, the blocks are conveyed to an integrated airflow drying and opening equipment (drying and opening machine) through a conveying system. The machine rotates at high speed at 120℃ and 0.5 MPa with a speed of 115 r / min, and is dried and opened at the same time. After completion, the finished aramid pulp can be obtained by an automatic weighing and packaging system. A sample is taken and marked as sample A for subsequent parameter testing. Figure 2 The image shown is an SEM image of the sample obtained in this embodiment. Measurements show that the sample is uniform in size and its length is distributed in the range of 0.8 to 0.97 mm, which meets the size requirements of the finished aramid pulp.

[0060] Example 2

[0061] The difference between this embodiment and embodiment 1 is that: in step (2), the water flow rate is 190 kg / h, and the stirring speed of the buffer tank is 35 r / min; in step (4), the filtration flow rate of the belt filter is 200 kg / h; all other parameters are the same as in embodiment 1. The sample of the finished product obtained in this embodiment is marked as sample B.

[0062] Example 3

[0063] The difference between this embodiment and Embodiment 1 is as follows: in step (2), the water flow rate is 200 kg / h, and the stirring speed of the buffer tank is 34 r / min; in step (3), the speed of the high-shear disperser in the primary grinding system is 40 r / min, and the speed of the high-shear disperser in the secondary grinding system is 58 r / min; in step (4), the filtration flow rate of the belt filter is 210 kg / h, and the speed of the drying and opening integrated machine is 126 r / min; all other parameters are the same as in Embodiment 1. The sample of the finished product obtained in this embodiment is marked as Sample C.

[0064] The para-aramid pulp prepared by the above method has uniform length and stable quality, and the production efficiency is significantly improved compared with the existing technology. Traditional pulping processes take approximately 2-2.5 hours, which is time-consuming and inefficient; existing tandem pulping processes take approximately 1.5-2 hours, while the multi-stage tandem pulping process provided in this application takes only about 1.16 hours, an improvement of nearly 20% compared to existing tandem pulping processes, effectively improving production efficiency and reducing production costs.

[0065] Comparative Example 1

[0066] The difference between this comparative example and Example 1 is that the refining system uses an existing tandem refining process, consisting of two refiners connected in series, with a total refining time of 1.5–2 hours. The remaining steps and process parameters are the same as in Example 1. The finished product obtained in this comparative example is taken as sample 1.

[0067] Comparative Example 2

[0068] The difference between this comparative example and Example 2 is that the refining system uses an existing tandem refining process, consisting of two refiners connected in series, with a total refining time of 1.5–2 hours. The remaining steps and process parameters are the same as in Example 2. The finished product obtained in this comparative example is taken as sample 2.

[0069] Comparative Example 3

[0070] The difference between this comparative example and Example 3 is that the refining system uses an existing tandem refining process, consisting of two refiners connected in series, with a total refining time of 1.5–2 hours. The remaining steps and process parameters are the same as in Example 3. The finished product obtained in this comparative example is taken as sample 3.

[0071] Comparative Example 4

[0072] The difference between this comparative example and Example 1 is that: in step (2), a traditional feeding method is used, specifically, short fibers are added to the mixing vessel, then water is added, and the mixture is stirred and mixed. The mixture is then conveyed to the pulping system via a double-helix mixer. The remaining steps and process parameters are the same as in Example 1. The finished product obtained in this comparative example is sampled and labeled as sample a. The traditional feeding method takes more than 5 minutes longer than the continuous feeding method of this application and requires more manpower and resources.

[0073] Comparative Example 5

[0074] The difference between this comparative example and Example 2 is that: in step (2), a traditional feeding method is used for feeding (non-continuous feeding, the same as comparative example 4), while the remaining steps and process parameters are the same as in Example 2. The finished product obtained in this comparative example is taken as sample b.

[0075] Comparative Example 6

[0076] The difference between this comparative example and Example 3 is that: in step (2), a traditional feeding method is used for feeding (non-continuous feeding, the same as in Comparative Example 4), while the remaining steps and process parameters are the same as in Example 3. The finished product obtained in this comparative example is taken as a sample and marked as sample c.

[0077] Long filament fibers from the same batch were produced using the processes described in the above examples and comparative examples. The resulting samples underwent a series of performance parameter tests, and the results are shown in Table 1.

[0078] Table 1. Comparison of performance parameters of aramid pulp products obtained by the present invention and existing technologies.

[0079]

[0080] As can be seen from the comparison of parameters in Table 1, besides the significant improvement in production efficiency, the parameters of samples 1-3 obtained by the existing continuous production method for para-aramid pulp fluctuate greatly, indicating that the quality of the aramid pulp product is unstable and lacks uniformity. Furthermore, samples a-c obtained using the traditional discontinuous feeding method have high moisture content, due to excessive water absorption by the chopped fibers during the long feeding process. Continuous feeding effectively avoids this problem, resulting in a significant decrease in the moisture content of the finished aramid pulp. In contrast, the parameters of samples A-C obtained in Examples 1-3 of this application do not fluctuate significantly, indicating that the aramid pulp product obtained by the method provided in this application has stable quality and uniform size. The two-stage grinding system used in the efficient continuous production method of para-aramid pulp in this application significantly improves the grinding effect compared to the existing tandem grinding system. Combined with adjustments and improvements to other process steps, the method of this application balances efficiency and quality, possessing good economic benefits and promotional value.

[0081] In summary, the method for efficient and continuous production of para-aramid pulp provided by this invention has significant advantages over existing technologies in terms of improving production efficiency, reducing production costs, stabilizing output, improving product quality, and environmental benefits. It provides a more advanced, economical, and environmentally friendly solution for the production of high-quality para-aramid pulp.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for efficient and continuous production of para-aramid pulp, characterized in that: Includes the following steps: Surface modification of filament fibers; The surface modifier used in the surface modification step is fatty acid polyethylene glycol ester; Continuous feeding: Long filament fibers are cut into short fibers, and then water is added, mixed and stirred and transported simultaneously through a double spiral mixer to prepare a short fiber solution with a concentration of 2~4%. Two-stage pulping process: The aramid pulp in the short-cut fiber solution is sequentially passed through a primary pulping system and a secondary pulping system to achieve the desired length. Both the primary and secondary pulping systems consist of 4-6 high-shear dispersers connected in series, with the high-shear dispersers in the secondary pulping system rotating at a higher speed than those in the primary pulping system. The high-shear dispersers in the primary pulping system rotate at 35-45 r / min, while those in the secondary pulping system rotate at 40-60 r / min. After filtration, the pulp is dried and opened to obtain the finished para-aramid pulp. Before the chopped fiber solution enters the primary refining system, the following steps are also included: stirring in a buffer tank; and maintaining a constant liquid level in the buffer tank by adjusting the inlet and outlet flow rates of the buffer tank. When the chopped fiber solution enters the buffer tank, the primary refining system is turned on first. When the high-shear disperser speed in the primary refining system reaches the set value, the buffer tank can continuously feed material into the primary refining system. The double-helix mixer is equipped with a water inlet.

2. The method according to claim 1, characterized in that: The drying and opening process is carried out using an integrated drying and opening machine. The processing temperature is 105~125℃, the power is 0.3~0.6Mpa, the processing time is 15~30min, and the rotation speed is 110~130 r / min.

3. The method according to claim 1, characterized in that: The length of the chopped fibers is 3-6 mm, and the length of the aramid pulp in the slurry after two-stage pulping is 0.8-0.97 mm.

4. The method according to claim 1, characterized in that: The filtration process uses a belt filter with a filtration pressure of 0.4~0.8MPa and a filtration flow rate of 190~220kg / h.

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