Shrinkage shaping method of needled filter felt

Abstract

The invention provides a shrinkage shaping method of a needled filter felt, which comprises the steps of preheating, stretching, heat shaping, shrinkage, cold shaping and testing, and is characterized in that through double shaping of heat shaping and cold shaping, a mixed liquid cooling liquid of a liquid cooling liquid A and a liquid cooling liquid B is used for cold shrinkage shaping; and finally testing the aperture, the thickness, the tensile strength and the filtering efficiency of the needled filter felt to be qualified. The needled filter felt is shrunk and shaped by means of preheating, stretching, heat shaping, shrinking and cold shaping, the shaping effect of the needled filter felt is greatly improved by means of hot and cold shaping, and the shrinking and shaping effect of the needled filter felt is remarkably improved by using liquid cooling liquid containing chitosan, polydopamine, hyaluronic acid and artificial plasma during cold shaping. And pores of the needled filter felt are prevented from being blocked by the water-soluble liquid cooling liquid, so that the filtering effect of the needled filter felt is effectively ensured, and meanwhile, the shaping effect of the needled filter felt is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of needle-punched filter felts, and particularly to a method for shrinkage setting of needle-punched filter felts. Background Art

[0002] A needle-punched filter felt is a filter material made by a non-woven needle-punching process, and is widely used in industrial dust collection, smoke and dust treatment, etc. This material is usually made of polyester fiber, has excellent air permeability and a smooth surface, and through heat setting and other treatment methods, it is not easy to deform and is easy to clean ash. In particular, after the polyester needle-punched felt filter material is treated with water and oil repellency, it has excellent water repellency performance, is suitable for the smoke and dust environment with high moisture content or containing a small amount of oil, can prevent bag clogging, and prolong the service life.

[0003] In the heat setting process of the needle-punched filter felt, a roller is usually used to roll-press its surface, and its thickness is made uniform and its surface is made smooth during the process of passing through a heating oven. However, during the processing, the roller used for pressing is installed with a bearing seat. When processing needle-punched filter felts with different thicknesses, it is necessary to disassemble the bearing seat and adjust the position to press and process needle-punched filter felts with different thicknesses. It is inconvenient to adjust the position, and at the same time, it is time-consuming for manual adjustment, and the accuracy of manual up and down adjustment is limited, which has a certain impact on the processing of needle-punched filter felts.

[0004] The needle-punched filter felts in the prior art often use heat setting to set their shape, and this setting method will cause the needle-punched filter felt to have current deformation, and even damage the internal felt fiber structure of the needle-punched filter felt, greatly reducing the tensile strength of the felt fiber, seriously affecting the actual filtration effect and service life of the needle-punched filter felt. It is urgent to design a setting method of shrinkage type to process the needle-punched filter felt to improve its structural strength and service life. Summary of the Invention

[0005] Aiming at the deficiencies of the above-mentioned prior art, the main purpose of the present invention is to provide a method for shrinkage setting of needle-punched filter felts. The needle-punched filter felt realizes shrinkage setting through the methods of preheating, stretching, heat setting, shrinking, and cold setting. The setting effect of the needle-punched filter felt is greatly improved through heat and cold two-time setting. The shrinkage setting effect of the needle-punched filter felt is significantly improved by using a liquid coolant containing chitosan, polydopamine, hyaluronic acid, and artificial plasma during cold setting. By using a water-soluble liquid coolant, the clogging of the capillary pores of the needle-punched filter felt is avoided, effectively ensuring the filtration effect of the needle-punched filter felt while greatly improving the setting effect of the needle-punched filter felt.

[0006] To achieve the purpose of the present invention, the technical solution adopted is: A method for shrinkage setting of a needle-punched filter felt, and the specific operation steps of the shrinkage setting method of the needle-punched filter felt are as follows: S1. Preheating: Transfer the needled filter felt obtained by electrospinning to a preheating machine for preheating. The preheating temperature is controlled at 50 - 100 °C, the preheating time is 40 - 100 min, an inert gas with a flow rate of 5 - 13 L / h is introduced during preheating. After preheating, transfer the needled filter felt to a stretching machine for stretching; S2. Stretching: Control the temperature of the stretching machine at 60 - 100 °C and the tensile force at 100 - 500 N / m 2 , the stretching machine performs equal - force stretching on the needled filter felt horizontally and vertically. The acceleration of the tensile force from zero to the maximum tensile force is controlled at 20 - 50 N / min, and the stretching duration is 10 - 30 min; S3. Heat setting: Transfer the stretched needled filter felt isothermally to a heat - setting machine. Control the heat - setting temperature of the heat - setting machine at 60 - 100 °C, and perform hot - pressing and setting through a hot - pressing plate. The hot - pressing temperature is 80 - 90 °C, the hot - pressing time is 3 - 8 min, and the number of hot - pressing times is 5 - 8 times; S4. Shrinking: Transfer the heat - set needled filter felt isothermally to a shrinking machine. The initial temperature of the shrinking machine is 80 - 100 °C. The shrinking machine performs equal - force squeezing and shrinking on the needled filter felt horizontally and vertically. The shrinking force is 10 - 30 N / m 2 , the cooling rate is 3 - 5 °C / min. After cooling to room temperature, continue to shrink for 10 - 30 min; S5. Cold setting: Transfer the shrunk needled filter felt to a cold - setting machine for liquid - cooling setting. Control the temperature of the liquid - cooling liquid at 0 - 15 °C, and the liquid - cooling time is 60 - 150 min. The needled filter felt is completely immersed in the liquid - cooling liquid. After the liquid - cooling setting is completed, rinse the needled filter felt with isothermal deionized water until there is no residue of the liquid - cooling liquid on the surface of the needled filter felt; S6. Testing: Modify the shrunk and set needled filter felt, remove burrs and cut it into the required shape. Test the pore size, thickness, tensile strength and filtration efficiency of the needled filter felt through a testing machine. After passing the test, it can be packaged to obtain the shrunk and set needled filter felt.

[0007] Preferably, the inert gas introduced during preheating in step 1 of the shrinking and setting method is nitrogen, and steps 1 - 5 are all carried out in a nitrogen atmosphere, and the needled filter felt does not deform during preheating.

[0008] Preferably, in step 2 of the shrinking and setting method, the actual stretching area of the needled filter felt during stretching is 0.8 - 3.5 m 2 , the stretching shape is square, and the needled filter felt remains horizontal during stretching.

[0009] Preferably, during the heat setting in step 3 of the shrinkage setting method, the hot pressing plate performs hot pressing with equal force from both the upper and lower sides simultaneously. The single hot pressing time does not exceed 1 min, and the hot pressing interval time is 15 - 40 s.

[0010] Preferably, in step 4 of the shrinkage setting method, the shrinkage frequency during shrinkage is 20 - 50 times / min, and the high-temperature shrinkage time is 15 - 25 min.

[0011] Preferably, in step 5 of the shrinkage setting method, the liquid coolant used for cold setting is a mixed liquid of liquid coolant A and liquid coolant B. The mixing mass ratio of liquid coolant A and liquid coolant B in the mixed liquid is 1 - 3:2 - 5. The mass percentage of liquid coolant A in the liquid coolant is as follows: Chitosan hydrochloride 8 - 15%, Sodium sialate 3 - 6%, Polydopamine 12 - 23%, Ammonium chloride 4 - 13%, Sodium hydrogen phosphate 3 - 11%, Sodium bicarbonate 2 - 8%, Ammonia water 2 - 5%, Sodium hyaluronate 1 - 3%, Artificial plasma 15 - 30%, Water 40 - 60%.

[0012] Preferably, the mass percentage of liquid coolant B in the liquid coolant in step 5 of the shrinkage setting method is as follows: Chitosan hydrochloride 8 - 15%, Polydopamine 12 - 23%, Sodium hyaluronate 1 - 3%, Glucose 25 - 45%, Water 40 - 60%.

[0013] The shrinkage setting method of the needle-punched filter felt provided by the present invention has the following advantages: The needle-punched filter felt of the present invention realizes shrinkage setting through the methods of preheating, stretching, heat setting, shrinkage, and cold setting. The setting effect of the needle-punched filter felt is greatly improved through two heat and cold setting processes. The shrinkage setting effect of the needle-punched filter felt is significantly improved by using a liquid coolant containing chitosan, polydopamine, hyaluronic acid, and artificial plasma during cold setting. The capillary pores of the needle-punched filter felt are prevented from being blocked by the water-soluble liquid coolant, effectively ensuring the filtering effect of the needle-punched filter felt while greatly improving the setting effect of the needle-punched filter felt. Specific Embodiments

[0014] The following further elaborates and explains the present invention with specific embodiments.

[0015] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0016] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships in the technical solution, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. Example 1

[0017] A method for shrinkage setting of a needle-punched filter felt, and the specific operation steps of the shrinkage setting method of the needle-punched filter felt are as follows: S1. Preheating: Transfer the needle-punched filter felt obtained by electrospinning to a preheating machine for preheating. The preheating temperature is controlled at 55 °C, the preheating time is 100 min, an inert gas with a flow rate of 13 L / h is introduced during preheating, and after preheating, transfer the needle-punched filter felt to a stretching machine for stretching; S2. Stretching: Control the temperature of the stretching machine at 90 °C and the tensile force at 500 N / m 2 , the stretching machine performs equal-force stretching on the needle-punched filter felt in the transverse and longitudinal directions. The acceleration of the tensile force from zero to the maximum tensile force is controlled at 20 N / min, and the stretching duration is 30 min; S3. Heat setting: Transfer the stretched needle-punched filter felt isothermally to a heat setting machine, control the heat setting temperature of the heat setting machine at 90 °C, and perform hot pressing and setting through a hot pressing plate. The hot pressing temperature is 90 °C, the hot pressing time is 4 min, and the number of hot pressing times is 8 times; S4. Shrinkage: Transfer the heat-set needle-punched filter felt isothermally to a shrinkage machine. The initial temperature of the shrinkage machine is 90 °C. The shrinkage machine performs equal-force extrusion shrinkage on the needle-punched filter felt in the transverse and longitudinal directions. The shrinkage force is 20 N / m 2 , the cooling rate is 4 °C / min. After cooling to room temperature, continue to shrink for 20 min; S5. Cold setting: Transfer the shrunk needle-punched filter felt to a cold setting machine for liquid cooling setting. Control the temperature of the liquid cooling liquid at 0 °C, the liquid cooling time is 100 min, the needle-punched filter felt is completely immersed in the liquid cooling liquid. After the liquid cooling setting is completed, rinse the needle-punched filter felt with isothermal deionized water until there is no residue of the liquid cooling liquid on the surface of the needle-punched filter felt; S6. Testing: Modify the shrinkage-set needle-punched filter felt, remove burrs and cut it into the required shape. Test the pore size, thickness, tensile strength and filtration efficiency of the needle-punched filter felt through a testing machine. After passing the test, it can be packaged to obtain the shrinkage-set needle-punched filter felt.

[0018] Furthermore, the inert gas introduced during preheating in step 1 of the shrinkage setting method is nitrogen, and steps 1-5 are all carried out in a nitrogen atmosphere, and the needle-punched filter felt does not deform during preheating.

[0019] Further, in step 2 of the shrinking and shaping method, the actual stretching area of the needled filter felt during stretching is 2.0 m 2 , the stretching shape is square, and the needled filter felt remains horizontal during stretching.

[0020] Further, in step 3 of the shrinking and shaping method, during heat setting, the hot pressing plate performs hot pressing with equal force from both the upper and lower sides simultaneously. The single hot pressing time does not exceed 1 min, and the hot pressing interval time is 25 s.

[0021] Further, in step 4 of the shrinking and shaping method, the shrinking frequency during shrinking is 30 times / min, and the high-temperature shrinking time is 20 min.

[0022] Further, in step 5 of the shrinking and shaping method, the liquid coolant used for cold setting is a mixed liquid of liquid coolant A and liquid coolant B. The mixing mass ratio of liquid coolant A and liquid coolant B in the mixed liquid is 1 - 3:2 - 5. The mass percentage of liquid coolant A in the liquid coolant is as follows: Chitosan hydrochloride 10%, Sodium sialate 5%, Polydopamine 15%, Ammonium chloride 5%, Sodium hydrogen phosphate 5%, Sodium bicarbonate 5%, Ammonia water 2%, Sodium hyaluronate 3%, Artificial plasma 10%, Water 40%.

[0023] Further, the mass percentage of liquid coolant B in the liquid coolant in step 5 of the shrinking and shaping method is as follows: Chitosan hydrochloride 12%, Polydopamine 15%, Sodium hyaluronate 3%, Glucose 25%, Water 45%. Example 2

[0024] The difference between this example and Example 1 is: A shrinking and shaping method for a needled filter felt. The specific operation steps of the shrinking and shaping method for the needled filter felt are as follows: S1. Preheating: Transfer the needled filter felt obtained by electrospinning to a preheating machine for preheating. The preheating temperature is controlled at 60 °C, the preheating time is 80 min, an inert gas with a flow rate of 7 L / h is introduced during preheating, and after preheating, transfer the needled filter felt to a stretching machine for stretching; S2. Stretching: Control the temperature of the stretching machine to 85 °C and the tensile force to 200 N / m 2 , the stretching machine performs equal-force stretching on the needled filter felt in the horizontal and vertical directions. The acceleration of the tensile force from zero to the maximum tensile force is controlled at 20 N / min, and the stretching duration is 30 min; S3. Heat setting: The stretched needled filter felt is transferred to a heat setting machine isothermally. Control the heat setting temperature of the heat setting machine to be 85 °C, and perform hot pressing and setting through a hot pressing plate. The hot pressing temperature is 85 °C, the hot pressing time is 5 min, and the number of hot pressing times is 6 times; S4. Shrinking: The heat-set needled filter felt is transferred to a shrinking machine isothermally. The initial temperature of the shrinking machine is 85 °C. The shrinking machine performs equal-force extrusion and shrinking on the needled filter felt horizontally and longitudinally. The shrinking force is 15 N / m 2 , and the cooling rate is 4 °C / min. After cooling to room temperature, continue to shrink for 20 min; S5. Cold setting: Transfer the shrunk needled filter felt to a cold setting machine for liquid cooling setting. Control the temperature of the liquid cooling liquid to be 5 °C, and the liquid cooling time to be 120 min. The needled filter felt is completely immersed in the liquid cooling liquid. After the liquid cooling setting is completed, rinse the needled filter felt with isothermal deionized water until there is no residue of the liquid cooling liquid on the surface of the needled filter felt; S6. Testing: Modify the shrunk and set needled filter felt, remove burrs and cut it into the required shape. Test the pore size, thickness, tensile strength and filtration efficiency of the needled filter felt through a testing machine. After passing the test, it can be packaged to obtain the shrunk and set needled filter felt.

[0025] Further, the inert gas introduced during preheating in step 1 of the shrinking and setting method is nitrogen, and steps 1-5 are all carried out in a nitrogen atmosphere, and the needled filter felt does not deform during preheating.

[0026] Further, in step 2 of the shrinking and setting method, the actual stretching area of the needled filter felt during stretching is 1.0 m 2 , the stretching shape is square, and the needled filter felt remains horizontal during stretching.

[0027] Further, in step 3 of the shrinking and setting method, during heat setting, the hot pressing plate performs equal-force hot pressing from both the upper and lower sides at the same time. The single hot pressing time does not exceed 1 min, and the hot pressing interval time is 15 s.

[0028] Further, in step 4 of the shrinking and setting method, the shrinking frequency during shrinking is 50 times / min, and the high-temperature shrinking time is 15 min.

[0029] Further, in step 5 of the shrinking and setting method, the liquid cooling liquid used for cold setting is a mixed liquid of liquid cooling liquid A and liquid cooling liquid B. The mixing mass ratio of liquid cooling liquid A and liquid cooling liquid B in the mixed liquid is 1:1. The mass percentage of liquid cooling liquid A in the liquid cooling liquid is as follows: Chitosan hydrochloride 8%, Sodium sialate 3%, Polydopamine 12%, Ammonium chloride 4%, Sodium hydrogen phosphate 3%, Sodium bicarbonate 2%, Ammonia water 2%, Sodium hyaluronate 1%, Artificial plasma 15%, Water 50%.

[0030] Furthermore, the mass percentage of the liquid cooling liquid B in the liquid cooling liquid in step 5 of the shrinkage and shaping method is as follows: Chitosan hydrochloride 8%, polydopamine 12%, sodium hyaluronate 1%, glucose 25%, water 54%. Example 3

[0031] The difference between this embodiment and embodiments 1 and 2 is that: A shrinkage shaping method for needle-punched filter felt, the specific operation steps of the shrinkage shaping method for needle-punched filter felt are as follows: S1. Preheating: The needle-punched filter felt obtained by electrospinning is transferred to a preheating machine for preheating. The preheating temperature is controlled at 50 °C, the preheating time is 100 min, and an inert gas flow rate of 13 L / h is introduced during preheating. After the preheating is completed, the needle-punched filter felt is transferred to a stretching machine for stretching; S2. Stretching: The temperature of the stretching machine is controlled at 80 °C and the tension is controlled at 200 N / m 2 The stretching machine stretches the needle-punched filter felt horizontally and longitudinally with equal forces. The acceleration of the tension from zero to the maximum tension is controlled at 20 N / min, and the stretching duration is 30 min. S3. Heat setting: the stretched needle-punched filter felt isothermally transferred to a heat setting machine, the heat setting temperature of the heat setting machine is controlled to be 80°C, and the heat pressing is performed by a hot pressing plate, the hot pressing temperature is 80°C, the hot pressing time is 3 min, and the number of hot pressing is 8 times; S4. Shrinkage: The heat-set needle-punched filter felt is isothermally transferred to the shrinking machine. The initial temperature of the shrinking machine is 90°C. The shrinking machine squeezes and shrinks the needle-punched filter felt in the horizontal and vertical directions with a shrinking force of 15 N / m 2 , the cooling rate was 4℃ / min, and the shrinkage continued for 25 min after cooling to room temperature; S5. Cold setting: the shrunk needle-punched filter felt is transferred to a cold setting machine for liquid cooling setting, the liquid cooling liquid temperature is controlled to be 10°C, the liquid cooling time is 80 min, and the needle-punched filter felt is completely immersed in the liquid cooling liquid. After the liquid cooling setting is completed, the needle-punched filter felt is rinsed with isothermal deionized water until no liquid cooling liquid remains on the surface of the needle-punched filter felt; S6. Test: The shrunk and shaped needle-punched filter felt is modified, burrs are removed and it is cut into the required shape. The pore size, thickness, tensile strength and filtration efficiency of the needle-punched filter felt are tested by a testing machine. After the test is qualified, it is packaged to obtain the shrunk and shaped needle-punched filter felt.

[0032] Furthermore, the inert gas introduced during preheating in step 1 of the shrinkage and shaping method is nitrogen, and steps 1-5 are all carried out in a nitrogen atmosphere, and the needle-punched filter felt does not deform during preheating.

[0033] Further, in step 2 of the shrinking and shaping method, the actual stretching area of the needle-punched filter felt during stretching is 2.0 m 2 , the stretching shape is square, and the needle-punched filter felt remains horizontal during stretching.

[0034] Further, in step 3 of the shrinking and shaping method, during heat setting, the hot pressing plate performs hot pressing with equal force from both the upper and lower sides simultaneously. The single hot pressing time does not exceed 1 min, and the hot pressing interval time is 30 s.

[0035] Further, in step 4 of the shrinking and shaping method, the shrinking frequency during shrinking is 30 times / min, and the high-temperature shrinking time is 20 min.

[0036] Further, in step 5 of the shrinking and shaping method, the liquid coolant used for cold setting is a mixed liquid of liquid coolant A and liquid coolant B. The mixing mass ratio of liquid coolant A and liquid coolant B in the mixed liquid is 1:2. The mass percentage of liquid coolant A in the liquid coolant is as follows: Chitosan hydrochloride 8%, Sodium sialate 3%, Polydopamine 20%, Ammonium chloride 4%, Sodium hydrogen phosphate 3%, Sodium bicarbonate 2%, Ammonia water 2%, Sodium hyaluronate 1%, Artificial plasma 20%, Water 40%.

[0037] Further, the mass percentage of liquid coolant B in the liquid coolant in step 5 of the shrinking and shaping method is as follows: Chitosan hydrochloride 15%, Polydopamine 16%, Sodium hyaluronate 3%, Glucose 26%, Water 40%. Example 4

[0038] The differences between this example and Examples 1, 2, and 3 are as follows: A shrinking and shaping method for a needle-punched filter felt. The specific operation steps of the shrinking and shaping method for the needle-punched filter felt are as follows: S1. Preheating: Transfer the needle-punched filter felt obtained by electrospinning to a preheating machine for preheating. The preheating temperature is controlled at 50 °C, the preheating time is 60 min, an inert gas with a flow rate of 8 L / h is introduced during preheating, and after preheating, transfer the needle-punched filter felt to a stretching machine for stretching; S2. Stretching: Control the temperature of the stretching machine to 90 °C and the tensile force to 300 N / m 2 , the stretching machine performs equal-force stretching on the needle-punched filter felt horizontally and longitudinally. The acceleration of the tensile force from zero to the maximum tensile force is controlled at 20 N / min, and the stretching duration is 30 min; S3. Heat setting: Transfer the stretched needle-punched filter felt isothermally to a heat setting machine, control the heat setting temperature of the heat setting machine to 90 °C, and perform hot pressing and shaping through a hot pressing plate. The hot pressing temperature is 90 °C, the hot pressing time is 3 min, and the number of hot pressing times is 8 times; S4. Shrinkage: Transfer the heat-set needled filter felt isothermally to a shrinkage machine. The initial temperature of the shrinkage machine is 90 °C. The shrinkage machine performs equal-force extrusion shrinkage on the needled filter felt horizontally and vertically, and the shrinkage force is 30 N / m 2 , with a cooling rate of 3 °C / min. After cooling to room temperature, continue to shrink for 30 min; S5. Cold setting: Transfer the shrunk needled filter felt to a cold setting machine for liquid cooling setting. Control the temperature of the liquid cooling liquid to 10 °C and the liquid cooling time to 80 min. The needled filter felt is completely immersed in the liquid cooling liquid. After the liquid cooling setting is completed, rinse the needled filter felt with isothermal deionized water until there is no residue of the liquid cooling liquid on the surface of the needled filter felt; S6. Testing: Modify the shrunk and set needled filter felt, remove burrs and cut it into the required shape. Test the pore size, thickness, tensile strength and filtration efficiency of the needled filter felt through a testing machine. After passing the test, it can be packaged to obtain the shrunk and set needled filter felt.

[0039] Furthermore, the inert gas introduced during preheating in step 1 of the shrinkage and setting method is nitrogen, and steps 1-5 are all carried out in a nitrogen atmosphere, and the needled filter felt does not deform during preheating.

[0040] Furthermore, in step 2 of the shrinkage and setting method, the actual stretching area of the needled filter felt during stretching is 1.5 m 2 , the stretching shape is square, and the needled filter felt remains horizontal during stretching.

[0041] Furthermore, in step 3 of the shrinkage and setting method, during heat setting, the hot pressing plates perform equal-force hot pressing from both the upper and lower sides at the same time. The single hot pressing time does not exceed 1 min, and the hot pressing interval time is 40 s.

[0042] Furthermore, in step 4 of the shrinkage and setting method, the shrinkage frequency during shrinkage is 20 times / min, and the high-temperature shrinkage time is 15 min.

[0043] Furthermore, in step 5 of the shrinkage and setting method, the liquid cooling liquid used for cold setting is a mixed liquid of liquid cooling liquid A and liquid cooling liquid B. The mixing mass ratio of liquid cooling liquid A and liquid cooling liquid B in the mixed liquid is 3:5. The mass percentage of liquid cooling liquid A in the liquid cooling liquid is as follows: Chitosan hydrochloride 12%, Sodium sialate 3%, Polydopamine 15%, Ammonium chloride 7%, Sodium hydrogen phosphate 3%, Sodium bicarbonate 2%, Ammonia water 2%, Sodium hyaluronate 1%, Artificial plasma 15%, Water 40%.

[0044] Furthermore, the mass percentage of liquid cooling liquid B in the liquid cooling liquid in step 5 of the shrinkage and setting method is as follows: 15% chitosan hydrochloride, 20% polydopamine, 3% sodium hyaluronate, 25% glucose, 47% water.

[0045] In the present invention, the needle-punched filter felt is shrink-set through preheating, stretching, heat setting, shrinking, and cold setting. The heat and cold setting significantly improves the setting effect of the needle-punched filter felt. The shrink-setting effect of the needle-punched filter felt is significantly improved by using a liquid coolant containing chitosan, polydopamine, hyaluronic acid, and artificial plasma during cold setting. The water-soluble liquid coolant avoids clogging the capillary pores of the needle-punched filter felt, effectively ensuring the filtration effect of the needle-punched filter felt while greatly improving the setting effect of the needle-punched filter felt.

[0046] The technical solutions disclosed in the embodiments of the present invention have been introduced in detail above. Specific embodiments are used herein to elaborate on the principles and implementation manners of the embodiments of the present invention. The descriptions of the above embodiments are only applicable to help understand the principles of the embodiments of the present invention; at the same time, for those of ordinary skill in the art, according to the embodiments of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A shrinkage shaping method for needle-punched filter felt, characterized in that: The specific operation steps of the shrinkage shaping method of the needle-punched filter felt are as follows: S1. Preheating: The needle-punched filter felt obtained by electrospinning is transferred to a preheating machine for preheating, the preheating temperature is controlled at 50-100 ° C, the preheating time is 40-100 min, and an inert gas flow rate of 5-13 L / h is introduced during preheating. After the preheating is completed, the needle-punched filter felt is transferred to a stretching machine for stretching; S2. Stretching: Control the temperature of the stretching machine to 60-100 ℃ and the tension to 100-500 N / m 2 The stretching machine stretches the needle-punched filter felt horizontally and vertically with equal forces. The acceleration of the tension from zero to the maximum tension is controlled to be 20-50 N / min, and the stretching duration is 10-30 min. S3. Heat setting: the stretched needle-punched filter felt isothermally transferred to a heat setting machine, the heat setting temperature of the heat setting machine is controlled to be 60-100 ° C, and the heat pressing is performed by a hot pressing plate, the hot pressing temperature is 80-90 ° C, the hot pressing time is 3-8 min, and the number of hot pressing times is 5-8 times; S4. Shrinkage: The heat-set needle-punched filter felt is isothermally transferred to the shrinking machine. The initial temperature of the shrinking machine is 80-100°C. The shrinking machine squeezes and shrinks the needle-punched filter felt in the horizontal and vertical directions with a shrinking force of 10-30 N / m 2 , the cooling rate is 3-5 ℃ / min, and after cooling to room temperature, the shrinkage continues for 10-30 minutes; S5. Cold setting: the shrunk needle-punched filter felt is transferred to a cold setting machine for liquid cooling and setting, the liquid cooling liquid temperature is controlled to be 0-15°C, the liquid cooling time is 60-150 min, and the needle-punched filter felt is completely immersed in the liquid cooling liquid. After the liquid cooling and setting is completed, the needle-punched filter felt is rinsed with isothermal deionized water until no liquid cooling liquid remains on the surface of the needle-punched filter felt; S6. Test: The shrunk and shaped needle-punched filter felt is modified, burrs are removed and it is cut into the required shape. The pore size, thickness, tensile strength and filtration efficiency of the needle-punched filter felt are tested by a testing machine. After the test is qualified, it is packaged to obtain the shrunk and shaped needle-punched filter felt.

2. The shrinkage and shaping method of needle-punched filter felt according to claim 1, characterized in that: The inert gas introduced during preheating in step 1 of the shrinkage shaping method is nitrogen, and steps 1 to 5 are all carried out in a nitrogen atmosphere, and the needle-punched filter felt does not deform during preheating.

3. The shrinkage and shaping method of needle-punched filter felt according to claim 1, characterized in that: The actual stretching area of ​​the needle-punched filter felt during stretching in step 2 of the shrinkage shaping method is 0.8-3.5 m 2 , the stretched shape is a square, and the needle-punched filter felt remains horizontal when stretched.

4. The shrinkage and shaping method of needle-punched filter felt according to claim 1, characterized in that: During heat setting in step 3 of the shrinkage setting method, the hot pressing plate performs heat pressing with equal force from both the upper and lower surfaces at the same time, the single heat pressing time does not exceed 1 minute, and the heat pressing interval time is 15-40 seconds.

5. The shrinkage and shaping method of needle-punched filter felt according to claim 1, characterized in that: The shrinking frequency during shrinking in step 4 of the shrinking and shaping method is 20-50 times / min, and the high-temperature shrinking time is 15-25 min.

6. The shrinkage and shaping method of needle-punched filter felt according to claim 1, characterized in that: The liquid cooling liquid used for cold setting in step 5 of the shrinkage setting method is a mixture of liquid cooling liquid A and liquid cooling liquid B, the mass ratio of liquid cooling liquid A to liquid cooling liquid B in the mixture is 1-3:2-5, and the mass percentage of liquid cooling liquid A in the liquid cooling liquid is as follows: Chitosan hydrochloride 8-15%, sodium sialate 3-6%, polydopamine 12-23%, ammonium chloride 4-13%, sodium hydrogen phosphate 3-11%, sodium bicarbonate 2-8%, ammonia water 2-5%, sodium hyaluronate 1-3%, artificial plasma 15-30%, water 40-60%.

7. The shrinkage and shaping method of needle-punched filter felt according to claim 6, characterized in that: The mass percentage of the liquid cooling liquid B in the liquid cooling liquid in step 5 of the shrinkage and shaping method is as follows: Chitosan hydrochloride 8-15%, polydopamine 12-23%, sodium hyaluronate 1-3%, glucose 25-45%, water 40-60%.