A device for cleaning PBO fibers

Abstract

The utility model discloses a PBO fiber cleaning device relates to PBO fiber production technical field, including solvent tank and cleaning tank, the bottom of solvent tank is equipped with the water outlet, and the top of solvent tank is equipped with the water inlet and reflux water port, is equipped with the porous water outlet pipe in the cleaning tank, and the porous water outlet pipe is equipped with detachable porous sleeve pipe, the porous water outlet pipe is the hollow cylinder structure of top end closure, and the bottom of porous water outlet pipe is connected with the water outlet of solvent tank through the water inlet pipe, and the side of porous water outlet pipe is provided with a plurality of water outlets, and the top of cleaning tank is equipped with the overflow port, and the overflow port is connected with the reflux water port of solvent tank, the bottom of cleaning tank and solvent tank is provided with the water drain respectively. Realized PBO fiber impurity efficient removal, dielectric performance optimization and the multiple target of mechanical property reservation, and have the compatibility of industrialization batch production simultaneously, provide the feasible path for the large -scale preparation of low dielectric high -performance PBO fiber.

Description

Technical Field

[0001] This utility model relates to the field of PBO fiber production technology, and in particular to a PBO fiber cleaning device. Background Technology

[0002] With the rapid development of electronic information technology, electronic devices are constantly evolving towards miniaturization, lightweighting, and high performance. In the field of high-frequency, high-speed transmission, the demand for materials with low dielectric properties is increasing. PBO (poly(p-phenylenebenzodioxazole)) fiber possesses excellent properties such as high strength, high modulus, and high flame retardancy, making it the most superior among organic synthetic fibers. Although PBO fiber boasts high strength, high modulus, excellent heat resistance, and chemical stability, leading to its widespread application in aerospace, electronic information, and advanced composite materials, the relatively high dielectric constant of traditional PBO fibers limits its application in high-frequency, high-speed, and microwave transmission.

[0003] Utility model patent CN222499495U discloses a PBO fiber alkaline washing and circulating cleaning device. This device is a two-stage alkaline washing unit, equipped with a temperature sensor and an alkali concentration meter, and a solvent concentration adjustment device. It can monitor the alkali concentration and temperature in real time, enabling timely diffusion and escape of the solvent inside the PBO fiber. By adjusting the angle of the guide roller, the nascent fiber is wound around the roller surface in multiple turns, effectively increasing the fiber alkaline washing residence time. It has advantages such as high alkaline washing efficiency and effective reduction of residual phosphorus content in PBO fibers. This PBO fiber alkaline washing and circulating cleaning device can not only meet the alkaline washing process requirements under different spinning processes, but is also more suitable for industrial fiber production.

[0004] However, this patent describes a cleaning device for continuous production lines, which has limited cleaning effectiveness. In actual production, the spinning speed of liquid crystal spinning is 150-500 m / min. Under such high spinning speeds and limited cleaning equipment conditions, the effective cleaning time is only a few minutes. Furthermore, the total phosphorus content of the phosphate extracted from PBO fibers from the laminator is approximately 50%. Within a few minutes, only about 1% of the total phosphorus content can be reduced. The remaining 1% of total phosphorus content, due to the reduced concentration and slower exchange rate, along with the gradual maturation of the fiber sheath, requires prolonged treatment with high-temperature hot water to remove the remaining 1% of phosphate. The limited processing time of this patent makes it impossible to remove the residual effective dielectric components from the PBO fibers. Utility Model Content

[0005] This invention aims to provide a PBO fiber cleaning device, which adopts a combination design of a porous water outlet pipe and a detachable porous sleeve. The water outlet of the porous water outlet pipe can spray out cleaning agent to directly rinse the PBO fibers rolled on the porous sleeve, ensuring full contact between the cleaning agent and the fiber. This reduces the effective dielectric component inside the PBO fiber, thereby lowering its dielectric constant and obtaining low-dielectric, high-performance PBO fibers. It achieves multiple goals of efficient removal of impurities, optimization of dielectric properties, and preservation of mechanical properties in PBO fibers. At the same time, it is adaptable to industrial mass production, providing a feasible path for the large-scale preparation of low-dielectric, high-performance PBO fibers, and combining technological innovation with industrial practicality.

[0006] To achieve the above-mentioned objectives, the technical solution of this utility model is as follows: A PBO fiber cleaning device includes a solvent tank and a cleaning tank. The solvent tank has an outlet at the bottom and an inlet and a return outlet at the top. The cleaning tank is equipped with a multi-hole water outlet pipe, and the multi-hole water outlet pipe is covered with a detachable multi-hole sleeve. The porous water outlet pipe is a hollow cylindrical structure with a closed top. The bottom end of the porous water outlet pipe is connected to the water outlet of the solvent tank through a water inlet pipe. Multiple water outlet holes are provided on the side of the porous water outlet pipe. An overflow port is provided on the top of the cleaning tank, and the overflow port is connected to the return water port of the solvent tank.

[0007] The porous sleeve has a double-layer stainless steel structure, including an inner layer and an outer layer, with a clearance fit between the inner and outer layers. Multiple through holes are provided on the sides of the inner and outer layers, with the spacing and diameter of the through holes in the inner layer being larger than those in the outer layer.

[0008] The cleaning tank has a water tank cover, which can be closed to reduce water evaporation, heat loss, and noise.

[0009] The cleaning tank is equipped with multiple perforated water outlet pipes, which are connected to the water inlet pipes respectively.

[0010] The bottom of the cleaning tank is provided with a connecting pipe, and the water inlet pipe is connected to the multi-hole water outlet pipe through the connecting pipe.

[0011] The inlet pipe is equipped with a water pump and a pressure gauge.

[0012] The solvent tank is equipped with a pressure relief pipe, one end of which is connected to the top of the solvent tank and the other end of which is connected to the water inlet pipe.

[0013] The water inlet pipe is equipped with a separate water flow control switch, which can adjust the water flow rate.

[0014] Two solvent tanks are provided, and the two solvent tanks are connected to a connecting pipe through a water inlet pipe.

[0015] The solvent tank is equipped with a heating device and a temperature sensor.

[0016] The bottom of the cleaning tank and the solvent tank are respectively provided with drain outlets.

[0017] The beneficial effects of this utility model are: 1. This utility model adopts a combination design of a multi-hole water outlet pipe and a detachable multi-hole sleeve. The water outlet of the multi-hole water outlet pipe can spray out cleaning agent (ultrapure water, NaOH solution) to directly rinse the PBO fibers rolled on the multi-hole sleeve, ensuring full contact between the cleaning agent and the fibers. This effectively dissolves and removes phosphoric acid and sodium phosphate impurities from the surface and interior of the fibers, solving the problem of impurity residue in traditional cleaning methods. The multi-hole sleeve uses a double-layer stainless steel structure, with fewer and larger pores in the inner layer and denser and smaller pores in the outer layer, ensuring a uniform cleaning effect of the cleaning agent when cleaning the fibers.

[0018] 2. This invention employs a two-step method: rinsing with ultrapure water followed by cleaning with NaOH solution. Ultrapure water initially dissolves water-soluble impurities, while the NaOH solution (pH=11) further neutralizes residual phosphoric acid and promotes the dissolution of sodium phosphate, ultimately removing 90% of the phosphoric acid and sodium phosphate impurities. This reduction in impurities directly lowers the polar dielectric component within the fiber, causing the dielectric constant of the PBO fiber at 10GHz to decrease from 3.8 before treatment to approximately 3.0, with a dielectric loss as low as 0.002, meeting the application requirements of low-dielectric materials (such as in high-frequency communication and electronic packaging).

[0019] 3. This invention achieves simultaneous cleaning of multiple rolls of fiber by setting up multiple porous water outlet pipes and connecting pipes, thus improving cleaning efficiency. The connecting pipes can balance the water flow pressure, avoiding uneven cleaning caused by uneven pressure. The dual cleaning tank design can hold ultrapure water and NaOH solution separately, eliminating the need to change cleaning agents mid-process, simplifying the operation process, and further improving continuity. Through parallel cleaning via multiple pipes and continuous operation of the dual cleaning tanks, batch processing of PBO fibers can be achieved, meeting the high-efficiency production capacity requirements of industrial production and solving the problem of connecting laboratory pilot-scale testing with industrial scale-up.

[0020] 4. In this utility model, the industry problem of impurities being difficult to remove due to high-speed spinning in PBO fiber production and impurities being sealed after the skin layer is perfected is addressed by optimizing the pretreatment and cleaning processes. While ensuring spinning efficiency and mechanical properties, the dielectric constant is effectively reduced, thus broadening the application of PBO fiber in the field of low dielectric and high-performance composite materials (such as aerospace, high-end electronics, etc.). Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the PBO fiber cleaning device of this utility model.

[0022] Figure 2 This is a schematic diagram of the structure of the porous sleeve of this utility model.

[0023] The components are as follows: 1. Solvent tank; 2. Cleaning tank; 3. Water outlet; 4. Water inlet pipe; 5. Return water outlet; 6. Multi-hole water outlet pipe; 7. Multi-hole sleeve; 8. Water outlet hole; 9. Overflow outlet; 10. Connecting pipe; 11. Heating device; 12. Temperature sensor; 13. Drain outlet; 14. Pressure relief pipe; 15. Water tank cover. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0025] Example 1 This embodiment provides a method such as Figure 1 The PBO fiber cleaning device shown includes a solvent tank 1 and a cleaning tank 2. The solvent tank 1 has a water outlet 3 at the bottom and a water inlet and a return water outlet 5 at the top. The cleaning tank 2 is equipped with a multi-hole water outlet pipe 6, and the multi-hole water outlet pipe 6 is covered with a detachable multi-hole sleeve 7. The porous water outlet pipe 6 is a hollow cylindrical structure with a closed top. The bottom end of the porous water outlet pipe 6 is connected to the water outlet 3 of the solvent tank 1 through the water inlet pipe 4. Multiple water outlet holes 8 are provided on the side of the porous water outlet pipe 6. The top of the cleaning tank 2 is provided with an overflow port 9, which is connected to the return water port 5 of the solvent tank 1. The bottom of the cleaning tank 2 and the solvent tank 1 are respectively provided with drain ports 13.

[0026] In this embodiment, under nitrogen conditions, polyphosphoric acid and phosphorus pentoxide are added sequentially to the reactor, stirred and cooled, and then terephthalic acid and 4,6-diaminoresorcinol hydrochloride are added respectively. Under continuous stirring, the temperature is raised to 130-150°C to complete prepolymerization and obtain a PBO prepolymer solution. The PBO prepolymer solution is then fed to a twin-screw extruder, where it undergoes high-polymerization to obtain a PBO spinning solution. The obtained PBO spinning solution is spun and then pre-dried to obtain PBO fibers with high water content. Approximately 1 kg of PBO fibers is wound onto a porous sleeve 7, which is then fitted onto a porous water outlet pipe 6. 150-300 L of ultrapure water at approximately 60-100°C is added to the solvent tank 1. The ultrapure water flows through the inlet pipe 4 into the porous water outlet pipe 6 and exits through the porous outlet. The water outlet 8 of pipe 6 sprays water to rinse the PBO fibers wound on the porous sleeve 7, dissolving and carrying away the phosphoric acid and sodium phosphate impurities on the PBO fibers. After repeating the cycle for 1 hour, ultrapure water is discharged, and 150-300L of room temperature NaOH solution with a pH of about 11 is added. The water is then circulated again for 0.5 hours. The final cleaning effect can remove 90% of the phosphoric acid and sodium phosphate impurities, reducing the effective dielectric components inside the PBO fibers and thus lowering their dielectric constant. The resulting PBO fibers are then dried and heat-treated to obtain high-performance, high-modulus PBO fibers. The resulting low-dielectric, high-performance PBO fibers have a tensile strength of 5.0-6.0 GPa, a tensile elastic modulus of 250-300 GPa, a dielectric constant of 3.1 at 10 GHz, and a dielectric loss of 0.002.

[0027] In this embodiment, the cleaning tank 2 is also provided with a water tank cover 15, which can be covered to reduce water evaporation, heat loss and noise.

[0028] Example 2 The difference between this embodiment and Embodiment 1 is that, in this embodiment, as... Figure 2 As shown, the porous sleeve 7 has a double-layer stainless steel structure, including an inner layer and an outer layer, with a gap fit between the inner and outer layers. Multiple through holes are provided on the sides of the inner and outer layers respectively, and the spacing and diameter of the through holes in the inner layer are larger than those in the outer layer.

[0029] In this embodiment, the double-layer stainless steel porous sleeve 7 has an inner and outer layer with a gap fit, and the spacing and diameter of the through holes in the inner layer are larger than those in the outer layer. Its function is to allow the cleaning agent to be dispersed first through the inner layer and then sprayed out through the outer layer, making the water flow more even and gentle in rinsing the PBO fibers. This ensures sufficient contact between the cleaning agent and the fibers to improve the impurity removal effect, while avoiding damage to the fibers from excessively strong water flow. Furthermore, the stainless steel material combines corrosion resistance and durability, making it suitable for various cleaning environments.

[0030] Example 3 The difference between this embodiment and Embodiment 1 is that, in this embodiment, the cleaning tank 2 is provided with multiple perforated water outlet pipes 6, which are respectively connected to the water inlet pipe 4. A connecting pipe 10 is provided at the bottom of the cleaning tank 2, and the water inlet pipe 4 is connected to the perforated water outlet pipes 6 through the connecting pipe 10. The remaining structure is the same as in Embodiment 1.

[0031] In this embodiment, the solvent tank 1 is equipped with a pressure relief pipe 14. One end of the pressure relief pipe 14 is connected to the top of the solvent tank 1, and the other end is connected to the water inlet pipe 4. The water inlet pipe 4 is equipped with a separate water flow control switch to adjust the water flow rate. The pressure relief pipe 14 connecting the top of the solvent tank 1 to the water inlet pipe 4 can release excessive pressure inside the tank, preventing damage to the tank due to excessive pressure and ensuring the safety of the device. The water flow control switch on the water inlet pipe 4 can adjust the water flow rate, allowing for precise control of the detergent supply according to cleaning needs, ensuring cleaning effectiveness while avoiding water waste, and improving operational flexibility and safety.

[0032] In this embodiment, by setting multiple perforated water outlet pipes 6 inside the cleaning tank 2, and each perforated water outlet pipe 6 is fitted with a perforated sleeve 7, multiple rolls of PBO fibers can be cleaned simultaneously, improving cleaning efficiency. The water flow from the inlet pipe 4 is evenly introduced into the perforated water outlet pipes 6 through the connecting pipe 10, avoiding uneven cleaning of the PBO fibers wound on different perforated sleeves 7 due to uneven pressure.

[0033] Example 4 The difference between this embodiment and Embodiment 1 is that, in this embodiment, the water inlet pipe 4 is equipped with a water pump and a pressure gauge. The rest of the structure is the same as in Embodiment 1.

[0034] In this embodiment, a water pump is installed on the water inlet pipe 4. The water and NaOH solution in the solvent tank 1 are pumped into the porous sleeve 7 in the cleaning tank 2 to rinse the PBO fibers. The pressure in the water inlet pipe 4 is monitored by a pressure gauge to prevent the cleaning effect from being poor due to excessive or insufficient pressure in the water inlet pipe 4.

[0035] Example 5 The difference between this embodiment and Embodiment 1 is that, in this embodiment, two solvent tanks 1 are provided, and the two solvent tanks 1 are respectively connected to the connecting pipe 10 through the water inlet pipe 4. The rest of the structure is the same as in Embodiment 1.

[0036] In this embodiment, ultrapure water and NaOH solution are added to the two solvent tanks 1 respectively. First, the water pump of the solvent tank 1 containing ultrapure water is started to circulate and clean the PBO fiber. After circulating for 1 hour, the water pump is turned off and the ultrapure water in the cleaning tank 2 is drained. Then, the water pump of the solvent tank 1 containing NaOH solution is started to circulate and clean the PBO fiber, and the water is circulated and cleaned again for 0.5 hours.

[0037] Example 6 The difference between this embodiment and Embodiment 1 is that, in this embodiment, a heating device 11 and a temperature sensor 12 are provided inside the solvent tank. The rest of the structure is the same as in Embodiment 1.

[0038] In this embodiment, the ultrapure water or NaOH solution is heated by the heating device 11 in the solvent tank 1, so that the ultrapure water or NaOH solution is kept in the range of 60-100°C during the circulating cleaning of PBO fibers, thus ensuring the cleaning quality.

[0039] In this embodiment, the heating device 11 is a heating coil installed on the inner wall of the solvent tank 1, and the temperature sensor 12 is a T-111S leaded armored thermocouple.

[0040] In summary, during the production of PBO fibers, maintaining a certain spinning rate and tension is necessary to ensure continuous and efficient spinning, as well as the performance of the PBO fibers. This requires a very high spinning rate. However, PBO fibers still contain a large amount of phosphoric acid and phosphate polymers after the wet spinning stage, which are difficult to completely remove by washing at high-speed spinning. Furthermore, after alkali treatment and drying, the outer layer of the PBO fibers becomes more refined, making the removal of phosphoric acid and its polymers even more difficult. This invention innovatively uses slightly dried PBO fibers, preserving both the production capacity and mechanical properties of PBO fibers while maintaining the operability of impurity treatment. After treatment with a self-made impurity removal device, followed by drying and heat treatment, the resulting PBO fibers achieve a dielectric constant of 3.1 at 10 GHz, a reduction of 0.7 from the original dielectric constant of 3.8. Moreover, this invention can meet the needs of industrial production and can process fibers in batches.

[0041] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this utility model.

Claims

1. A PBO fiber cleaning device, characterized in that: It includes a solvent tank (1) and a cleaning tank (2). The solvent tank (1) has an outlet (3) at the bottom and an inlet and a return outlet (5) at the top. The cleaning tank (2) is equipped with a multi-hole water outlet pipe (6), and the multi-hole water outlet pipe (6) is covered with a detachable multi-hole sleeve (7). The porous water outlet pipe (6) is a hollow cylindrical structure with a closed top. The bottom end of the porous water outlet pipe (6) is connected to the water outlet (3) of the solvent tank (1) through the water inlet pipe (4). Multiple water outlet holes (8) are provided on the side of the porous water outlet pipe (6). The top of the cleaning tank (2) is provided with an overflow port (9), which is connected to the return water port (5) of the solvent tank (1).

2. The PBO fiber cleaning device according to claim 1, characterized in that: The porous sleeve (7) is a double-layer stainless steel structure, including an inner layer and an outer layer. The inner layer and the outer layer are fitted with a gap. The sides of the inner layer and the outer layer are respectively provided with multiple through holes. The spacing and diameter of the through holes in the inner layer are larger than those in the outer layer.

3. The PBO fiber cleaning device according to claim 1, characterized in that: The cleaning tank (2) is equipped with multiple perforated water outlet pipes (6), which are connected to the water inlet pipe (4) respectively.

4. The PBO fiber cleaning device according to claim 3, characterized in that: The bottom of the cleaning tank (2) is provided with a connecting pipe (10), and the water inlet pipe (4) is connected to the multi-hole water outlet pipe (6) through the connecting pipe (10).

5. The PBO fiber cleaning device according to claim 1, characterized in that: The inlet pipe (4) is equipped with a water pump and a pressure gauge.

6. The PBO fiber cleaning device according to claim 4, characterized in that: Two solvent tanks (1) are provided, and the two solvent tanks (1) are connected to the connecting pipe (10) through the water inlet pipe (4).

7. The PBO fiber cleaning device according to claim 1, characterized in that: The solvent tank (1) is equipped with a heating device (11) and a temperature sensor (12).

8. The PBO fiber cleaning device according to claim 1, characterized in that: The bottom of the cleaning tank (2) and the solvent tank (1) are respectively provided with drain outlets (13).

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