Alkali-washing circulating cleaning equipment for PBO fibers

Abstract

The utility model belongs to the technical field of high-performance fiber production, and particularly relates to PBO (poly (p-phenylenebenzobisoxazole)) fiber alkali-washing circulating cleaning equipment. The equipment is a two-stage alkali washing device, is provided with a temperature sensor and an alkali liquor concentration meter, and is equipped with a solvent concentration adjusting device, so that the concentration and temperature of alkali liquor can be detected in real time, and timely diffusion and escape of a solvent in the PBO fiber are realized. By adjusting the angle of the godet roller, multi-circle winding of nascent fibers on the surface of the roller is achieved, the alkali washing retention time of the fibers is effectively prolonged, and the method has the advantages of being high in alkali washing efficiency, effectively reducing the residual phosphorus content of the PBO fibers and the like. The PBO fiber alkali washing circulating cleaning equipment not only can meet the alkali washing process requirements under different spinning processes, but also is more suitable for industrial fiber production.

Description

Technical Field

[0001] The utility model belongs to the technical field of high-performance fiber production, and in particular relates to a PBO fiber alkali washing circulation cleaning device. Background Art

[0002] Poly(p-phenylene benzobisoxazole) (PBO) fiber is a high-performance organic fiber with the best comprehensive performance at present. It has the characteristics of high strength, high modulus, high temperature resistance and high flame retardancy. The fiber strength can reach 5.8GPa, the high modulus fiber modulus is 280GPa, the limiting oxygen index (LOI) is 68, and the maximum decomposition temperature can reach 650℃. It is known as the super fiber of the 21st century. PBO fiber and its composite materials are widely used in the civilian field, bulletproof and impact-resistant materials, weapons and equipment, and other military and aerospace fields. Therefore, PBO fiber and its fiber-reinforced composite materials have always been a hot topic in military and civilian research.

[0003] PBO fiber uses polyphosphoric acid as solvent, which acts as both solvent and initiator in the PBO polymerization reaction. After the PBO spinning solution is ejected from the spinneret assembly, it enters the coagulation bath for coagulation and molding. At this time, the solvent inside the PBO fiber still contains a large amount of phosphoric acid solvent. The nascent fiber coming out of the coagulation bath needs to go through alkali washing and water washing processes to remove the residual phosphoric acid inside the fiber. The alkali washing process of PBO fiber is a double diffusion process. The temperature and concentration of the alkali washing solution play a crucial role in the removal of phosphoric acid and the final performance of the fiber.

[0004] PBO is a macromolecular structure of aromatic heterocyclic rigid chains, with high intrinsic viscosity of the polymer, poor fiber spinnability, easy surface crusting of the spinning solution after passing through the coagulation liquid, and difficulty in removing the phosphoric acid solvent from the inside of the fiber, which restricts the improvement of fiber aging resistance and mechanical properties. How to solve the above problems has become one of the problems to be solved in this field. Utility Model Content

[0005] In view of the problems of the prior art, the utility model provides a PBO fiber alkali washing circulation cleaning equipment. The equipment is a two-stage alkali washing device, and is provided with a temperature sensor and an alkali solution concentration meter, and is equipped with a solvent concentration adjustment device, which can detect the alkali solution concentration and temperature in real time. The timely diffusion and escape of the solvent inside the PBO fiber is achieved. By adjusting the angle of the guide roller, the primary fiber is wound on the roller surface for multiple turns, which effectively increases the fiber alkali washing residence time, has the advantages of high alkali washing efficiency, and effectively reduces the residual phosphorus content of the PBO fiber. The PBO fiber alkali washing circulation cleaning equipment can not only meet the alkali washing process requirements under different spinning processes, but also is more suitable for industrial fiber production.

[0006] A PBO fiber alkali washing circulation cleaning device consists of a two-stage alkali washing device, wherein the first-stage alkali washing device and the second-stage alkali washing device are both composed of an alkali washing box, an alkali solution storage tank, and an alkali solution replenishing tank.

[0007] Wherein: a first wire guide roller and a second wire guide roller are arranged in the alkali washing box; an alkali solution spray pipe is arranged above the inclined surface formed by the first wire guide roller and the second wire guide roller; and a first overflow baffle is arranged at the bottom outlet of the alkali washing box.

[0008] The alkali solution storage tank is provided with a temperature sensor, an alkali solution concentration meter and a heating device; the alkali solution storage tank is connected to the alkali solution spray pipe of the alkali washing box through a water inlet pipeline, and is connected to the bottom outlet of the alkali washing box through a return water pipeline.

[0009] The waste liquid outlet of the alkali solution storage tank is connected to the waste liquid tank through a pipeline, and a valve is arranged on the pipeline.

[0010] The alkali solution replenishing tank is connected with the alkali solution storage tank through a pipeline.

[0011] Preferably, a filter screen is provided at the bottom outlet of the alkali washing box, which can filter out some impurities and can be cleaned in time.

[0012] Preferably, an inlet wire guide rod is arranged at the fiber inlet position of the primary alkali washing device, and an outlet wire guide rod is arranged at the fiber outlet position of the primary alkali washing device.

[0013] Preferably, the height of the first overflow baffle is equal to half the height of the second wire guide roller. This arrangement allows the lower half of the second wire guide roller to be always immersed in the alkali solution, so that the fiber can be washed more fully in the alkali solution and the residual solvent in the fiber can be better removed.

[0014] Preferably, a water pump and / or a flow meter is provided on the water inlet pipeline of the alkali solution storage tank; and a valve is provided on the return water pipeline.

[0015] Preferably, a water pump and / or a flow meter is provided on the pipeline between the alkali solution replenishing tank and the alkali solution storage tank.

[0016] Preferably, a second overflow baffle is provided at the waste liquid outlet of the alkali liquid storage tank.

[0017] Preferably, the first godet roller can adjust its inclination angle, and more preferably, the adjustable angle is ±1-10° (along the plane direction of the first godet roller and the second godet roller). By changing the inclination angle of the first godet roller, the number of turns of the fiber wrapped around the roller surface can be adjusted. The larger the angle of the first godet roller tilting to the upper left (away from the second godet roller), the more turns the fiber can wrap around the roller surface and the longer the residence time. The larger the angle of the first godet roller tilting to the lower right (close to the second godet roller), the fewer turns the fiber can wrap around the roller surface and the shorter the residence time.

[0018] Preferably, the concentration of alkali solution in the alkali solution storage tank of the primary alkali washing device is 1-8%, and the concentration of alkali solution in the alkali solution storage tank of the secondary alkali washing device is 0.1-2%. According to the principle of solvent phase separation inside the fiber, two alkali washing tanks with different concentration gradients are used to alkali wash the PBO fiber to avoid premature skinning of the primary fiber after alkali washing, which affects the diffusion of phosphoric acid solvent inside the fiber.

[0019] Preferably, the temperature of the alkaline washing solution is in the range of 20 to 70°C.

[0020] The specific working process of the PBO fiber alkali washing cycle cleaning equipment of the utility model is as follows:

[0021] After the PBO spinning solution passes through the spinning system and solidification, it becomes the primary fiber. The primary fiber is pulled through the imported wire rod and then wound on the first wire guide roller and the second wire guide roller of the alkali washing box of the primary alkali washing device. The alkali solution passes through the alkali solution spray pipe to clean the fiber. The phosphoric acid solvent in the fiber interacts with the alkali solution and diffuses. The specific circulation method is that the alkali solution in the alkali solution storage tank enters the alkali washing box through the alkali solution spray pipe through the water pump and the flow meter. The alkali solution is in continuous contact with the primary fiber. When the alkali solution level in the alkali washing box reaches the height of the first overflow baffle, it begins to flow back into the alkali solution storage tank. In this process, the alkali solution concentration continues to decrease. When it is lower than the lowest concentration setting value, the high-concentration alkali solution in the alkali solution replenishment tank begins to enter the alkali solution storage tank. When the concentration reaches the highest setting value, the alkali solution is stopped. During the replenishment process, when the alkali solution level is higher than the second overflow baffle, the excess alkali solution enters the waste liquid tank.

[0022] After passing through the wire guide rod at the exit of the primary alkali washing device, the fiber enters the secondary alkali washing device, where it is also wound on the wire guide roller for spray cleaning, and the diffusion and escape of internal phosphoric acid are continued. The alkali solution circulation process is the same as that of the primary alkali washing device, and finally the fiber is guided out of the exit of the secondary alkali washing device to complete the alkali washing procedure. After the primary fiber comes out of the secondary alkali washing device, it enters the subsequent process links.

[0023] In the utility model, a temperature sensor, an alkali solution concentration meter and a heating device are respectively arranged in the alkali solution storage tank, which are used to detect and control the temperature and concentration value of the alkali solution in the alkali solution storage tank, thereby ensuring the stability of the concentration and temperature of the alkali solution, which is conducive to faster and more stable removal of the phosphoric acid solvent from the inside of the fiber.

[0024] The alkali solution storage tank is directly connected to the alkali washing box and the alkali solution replenishing tank by pipelines. The alkali washing circulation device can realize real-time detection of alkali solution concentration and automatic replenishment of alkali solution, and these can be further automated by utilizing existing technologies (such as PLC).

[0025] In summary, the PBO fiber alkali washing circulation cleaning equipment provided by the utility model can realize the cleaning of fibers with alkali solutions of different concentrations. The equipment can adjust the residence time of PBO fibers in the alkali washing solution, adjust the alkali washing flow rate, accelerate the flow of the alkali washing solution, promote the contact between the fibers and the alkali solution, increase the relative movement between the alkali solution and the fibers, and improve the solvent removal effect. The lower half of the second guide roller of the alkali washing box is immersed in the alkali solution, which realizes the timely diffusion, escape and dilution of the solvent inside the fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the utility model;

[0027] In the figure, 1 is an alkali washing box, 2 is a first wire guide roller, 3 is an alkali solution spray pipe, 4 is a first overflow baffle, 5 is a filter screen, 6 is an alkali solution storage tank, 7 is a temperature sensor, 8 is an alkali solution concentration meter, 9 is a heating device, 10 is a water pump, 11 is a flow meter, 12 is a valve, 13 is a second overflow baffle, 14 is an alkali solution replenishing tank, 15 is a waste liquid tank, 16 is an inlet wire guide rod, 17 is an outlet wire guide rod, and 18 is a second wire guide roller. DETAILED DESCRIPTION

[0028] The following is a further detailed description of the above contents of the utility model through specific implementation methods in the form of embodiments, but this should not be understood as the scope of the above subject matter of the utility model being limited to the following examples. All technologies implemented based on the above contents of the utility model belong to the scope of the utility model. Unless otherwise specified, the following embodiments are all completed using conventional technical operations.

[0029] A PBO fiber alkali washing cycle cleaning equipment, such as Figure 1 As shown, the equipment is composed of a two-stage alkali washing device, wherein the first-stage alkali washing device and the second-stage alkali washing device are both composed of an alkali washing box 1, an alkali solution storage tank 6, and an alkali solution replenishing tank 14.

[0030] Wherein: the first wire guide roller 2 and the second wire guide roller 18 are arranged in the alkali washing box 1; an alkali solution spray pipe 3 is arranged above the inclined surface formed by the first wire guide roller 2 and the second wire guide roller 18; and a first overflow baffle 4 is arranged at the bottom outlet position of the alkali washing box 1.

[0031] The alkali solution storage tank 6 is provided with a temperature sensor 7, an alkali solution concentration meter 8 and a heating device 9; the alkali solution storage tank 6 is connected to the alkali solution spray pipe 3 of the alkali washing box 1 through a water inlet pipeline, and is connected to the bottom outlet of the alkali washing box 1 through a return water pipeline.

[0032] The waste liquid outlet of the alkali liquid storage tank 6 is connected to the waste liquid tank 15 through a pipeline, and a valve is arranged on the pipeline.

[0033] The alkali solution replenishing tank 14 is connected to the alkali solution storage tank 6 through a pipeline.

[0034] A filter screen 5 is provided at the bottom outlet of the alkaline washing box 1 .

[0035] The height of the first overflow baffle 4 is equivalent to half the height of the second guide roller 18 .

[0036] The water inlet pipe of the alkali solution storage tank 6 is provided with a water pump 10 and a flow meter 11; the return pipe is provided with a valve 12. The waste liquid outlet of the alkali solution storage tank 6 is provided with a second overflow baffle 13.

[0037] A water pump and a flow meter are provided on the pipeline between the alkali solution replenishing tank 14 and the alkali solution storage tank 6 .

[0038] The first guide wire roller 2 can adjust its inclination angle, and the adjustable angle is ±1 to 10°.

[0039] The concentration of alkali solution in the alkali solution storage tank of the primary alkali washing device is 1-8%, and the concentration of alkali solution in the alkali solution storage tank of the secondary alkali washing device is 0.1-2%.

[0040] An inlet wire guide rod 16 is arranged at the fiber inlet position of the primary alkali washing device, and an outlet wire guide rod 17 is arranged at the fiber outlet position of the primary alkali washing device. The wire guide rod is made of wear-resistant ceramic material.

[0041] In this embodiment, when it is working, the PBO spinning solution becomes a primary fiber after passing through the spinning system and coagulation forming, and the primary fiber is pulled through the imported wire rod and then wound on the first wire guide roller and the second wire guide roller of the alkali washing box of the primary alkali washing device, and the alkali solution is passed through the alkali solution spray pipe to clean the fiber, and the phosphoric acid solvent in the fiber interacts with the alkali solution and diffuses. The specific circulation method is that the alkali solution in the alkali solution storage tank enters the alkali washing box through the alkali solution spray pipe through the water pump and the flow meter, and the alkali solution is in continuous contact with the primary fiber. When the alkali solution level in the alkali washing box reaches the height of the first overflow baffle, it begins to flow back into the alkali solution storage tank. In this process, the alkali solution concentration continues to decrease. When it is lower than the minimum value set by the concentration, the high-concentration alkali solution in the alkali solution replenishment tank begins to enter the alkali solution storage tank. When the concentration reaches the maximum value set by the concentration, the replenishment is stopped. During the replenishment process, when the alkali solution level is higher than the second overflow baffle, the excess alkali solution enters the waste liquid tank.

[0042] After the fiber passes through the exit guide rod of the first-level alkali washing device, it enters the next-level alkali washing device, and is also wound on the guide roller for spray cleaning to continue the diffusion and escape of internal phosphoric acid. The alkali solution circulation process is consistent with the first-level alkali washing device. Finally, the fiber is exported through the exit of the second-level alkali washing device to complete the alkali washing procedure. After the primary fiber comes out of the second-level alkali washing device, it enters the subsequent process link. Two different concentration gradient alkali washing tanks are used to alkali wash the PBO fiber to avoid premature skinning of the primary fiber after alkali washing, which affects the diffusion of the phosphoric acid solvent inside the fiber.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A PBO fiber alkali washing cycle cleaning equipment, characterized in that: The equipment is composed of a two-stage alkali washing device, wherein the first-stage alkali washing device and the second-stage alkali washing device are both composed of an alkali washing box (1), an alkali liquid storage tank (6), and an alkali liquid replenishing tank (14); wherein: A first wire guide roller (2) and a second wire guide roller (18) are arranged in the alkali washing box (1); an alkali solution spray pipe (3) is arranged above the inclined surface formed by the first wire guide roller (2) and the second wire guide roller (18); and a first overflow baffle (4) is arranged at the bottom outlet of the alkali washing box (1); The alkali solution storage tank (6) is provided with a temperature sensor (7), an alkali solution concentration meter (8) and a heating device (9); the alkali solution storage tank (6) is connected to the alkali solution spray pipe (3) of the alkali washing box (1) through a water inlet pipeline, and is connected to the bottom outlet of the alkali washing box (1) through a water return pipeline; The waste liquid outlet of the alkali liquid storage tank (6) is connected to the waste liquid tank (15) through a pipeline, and a valve is provided on the pipeline; The alkali solution replenishing tank (14) is connected to the alkali solution storage tank (6) through a pipeline.

2. A PBO fiber alkali washing circulation cleaning equipment according to claim 1, characterized in that: A filter screen (5) is arranged at the bottom outlet of the alkali washing box (1).

3. A PBO fiber alkali washing circulation cleaning equipment according to claim 1, characterized in that: An inlet wire guide rod (16) is arranged at the fiber inlet position of the primary alkali washing device, and an outlet wire guide rod (17) is arranged at the fiber outlet position of the primary alkali washing device.

4. A PBO fiber alkali washing circulation cleaning equipment according to claim 1, characterized in that: The height of the first overflow baffle (4) is equivalent to half the height of the second guide roller (18).

5. The PBO fiber alkali washing circulation cleaning equipment according to claim 1 is characterized in that: A water pump (10) and / or a flow meter (11) is arranged on the water inlet pipeline of the alkali solution storage tank (6); and a valve (12) is arranged on the water return pipeline.

6. A PBO fiber alkali washing circulation cleaning equipment according to claim 1, characterized in that: A water pump and / or a flow meter is arranged on the pipeline between the alkali solution replenishing tank (14) and the alkali solution storage tank (6).

7. The PBO fiber alkali washing circulation cleaning equipment according to claim 1 is characterized in that: A second overflow baffle (13) is provided at the waste liquid outlet of the alkali liquid storage tank (6).

8. The PBO fiber alkali washing circulation cleaning equipment according to claim 1 is characterized in that: The first wire guide roller (2) can adjust its inclination angle, and the adjustable angle is ±1 to 10°.

9. A PBO fiber alkali washing circulation cleaning equipment according to claim 1, characterized in that: The concentration of alkali solution in the alkali solution storage tank of the primary alkali washing device is 1-8%, and the concentration of alkali solution in the alkali solution storage tank of the secondary alkali washing device is 0.1-2%.

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