Membrane suitable for hemofiltration and method of manufacture

Abstract

The application relates to the technical field of filtering membranes, and particularly discloses a membrane suitable for blood filtration and a manufacturing method, which comprises the following steps: step one: dissolving a polysulfone polyethylene glycol block copolymer in a casting solution solvent, dissolving through heating mechanical stirring, standing and degassing to obtain a clear casting solution with good dissolution; step two: uniformly coating the casting solution on a carrier through a film doctor, acquiring coating state data of the casting solution, obtaining a coating state value based on the coating state data, comparing and processing the coating state value with a preset coating state value requirement, and if the coating state value meets the preset coating state value requirement, entering step three; if the coating state value does not meet the preset coating state value requirement, continuing step two; step three: placing a glass plate or a plastic plate coated with the film into an oven for drying, heat-treating the initial film, modifying and processing the treated film, and obtaining the membrane for blood filtration, so that the processing quality and the yield of the membrane for blood filtration are improved.

Description

Technical Field

[0001] This invention relates to the field of filtration membrane technology, and more specifically to a membrane suitable for blood filtration and its manufacturing method. Background Technology

[0002] Blood filtration membranes can be used in hemodialysis, plasma separation, and other fields. For example, patent publication number CN110639375A discloses a highly stable hemodialysis membrane and provides a method for preparing such a membrane, including: preparing a casting solution from a polysulfone-based amphiphilic block copolymer and fabricating the membrane using a solution phase inversion method to obtain a highly stable hemodialysis membrane; the molecular weight of the polysulfone-based amphiphilic block copolymer is between 20-240 kDa, and the mass ratio of polysulfone blocks to hydrophilic blocks is between 2.4-8.2. The hemodialysis membrane of this invention not only has good permeability to small and medium-sized molecular toxins but also completely prevents dissolution and possesses permanent hydrophilicity.

[0003] In the existing technology, the coating quality of the casting solution on the carrier by the coating machine cannot be identified. When the coating quality of the casting solution on the carrier is unqualified, the subsequent processing of the film will waste a lot of time and labor costs, which has great limitations. Summary of the Invention

[0004] The purpose of this invention is to provide a membrane suitable for blood filtration and a manufacturing method thereof. This involves acquiring coating state data of the casting solution on a carrier, specifically by dividing the area of ​​the carrier coated with the casting solution into several coating sub-units, processing the coating thickness value of each sub-unit to obtain a coating consistency value, comparing the coating thickness value of each non-stable sub-unit with a preset requirement to obtain a coating thickness deviation value for each non-stable sub-unit, combining this with the non-stable area of ​​the non-stable sub-unit on the carrier to obtain a coating deviation baseline value, and finally combining this with the coating state of the scraper on the carrier, specifically acquiring the scraper's coating speed and pressure within the coating time, and obtaining a coating behavior value based on these values. This allows for monitoring of the coating quality of the casting solution from multiple dimensions.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for manufacturing a membrane suitable for blood filtration includes the following steps:

[0007] Step 1: Dissolve the polysulfone-polyethylene glycol block copolymer in the casting solution solvent. After heating and mechanical stirring to dissolve, and allowing it to stand to degas, a well-dissolved and clear casting solution is obtained.

[0008] Step 2: The casting solution is uniformly coated onto the carrier using a coating machine. The coating status data of the casting solution is acquired, and the coating status value is obtained based on the coating status data.

[0009] The coating status value is compared with the preset coating status value requirement.

[0010] If the coating state value meets the preset requirements for coating state value, proceed to step three;

[0011] If the coating state value does not meet the preset requirements for coating state value, then continue to step two;

[0012] Step 3: Place the coating carrier into an oven and dry it to obtain a preliminary membrane. Then, heat-treat the preliminary membrane and further modify it to obtain a membrane for blood filtration.

[0013] As a further aspect of the present invention: in step two, the coating status data includes coating consistency value, coating deviation from baseline value, and coating behavior value;

[0014] The coating continuity value is denoted as TL;

[0015] The deviation of the coating from the baseline value is denoted as TP;

[0016] The coating behavior value is denoted as TX;

[0017] Through formula The coating state data is calculated to obtain the coating state value Ti, where a1, a2, and a3 are all preset proportional coefficients, and a1, a2, and a3 are all greater than zero.

[0018] As a further aspect of the present invention: the process for obtaining the coating continuous value is as follows:

[0019] The area of ​​the carrier coated with the casting solution is divided into several coating sub-units according to its area;

[0020] Obtain the coating thickness value of the casting liquid for each coating subunit;

[0021] The coating thickness values ​​of the casting liquid of all coating sub-units are integrated to obtain the coating thickness value group of the casting liquid of the coating sub-unit;

[0022] The coating thickness values ​​of the casting liquid in the coating subunit are processed according to the variance calculation formula to obtain the coating variance value of the casting liquid coating thickness value of the coating subunit.

[0023] The coating thickness value of the casting liquid of the coating sub-unit is compared with the preset requirement of the coating thickness value of the casting liquid of the coating sub-unit to obtain the calibration sub-unit and the non-stator unit;

[0024] The ratio of the number of non-stator units to the number of coated sub-units is calculated to obtain the non-stator ratio of the coated sub-units.

[0025] The coating integral value is obtained by multiplying the non-fixed ratio of the coating sub-unit with the coating variance value of the casting liquid coating thickness value of the coating sub-unit.

[0026] As a further aspect of the present invention: the process for obtaining the coating thickness value of the casting solution is as follows:

[0027] An inscribed circle is constructed within the coating sub-unit, and several thickness sampling points are collected at the center and circumference of the inscribed circle.

[0028] The thickness value corresponding to each thickness acquisition point is collected, and the obtained thickness values ​​are summed and averaged to obtain the coating thickness value of the casting liquid corresponding to each coating sub-unit.

[0029] As a further aspect of the present invention: a coating subunit whose casting liquid coating thickness value meets the preset requirement of the casting liquid coating thickness value of the coating subunit is designated as a calibration subunit;

[0030] A coating sub-unit whose casting liquid coating thickness does not meet the preset requirement of the coating liquid coating thickness of the coating sub-unit is recorded as a non-stator sub-unit.

[0031] As a further aspect of the present invention: the process for obtaining the coating deviation from the baseline value is as follows:

[0032] Obtain the coating thickness value of the casting liquid for each non-stator unit;

[0033] The coating thickness value of the casting liquid for each non-stator unit is compared with the preset requirement of the coating thickness value of the coating liquid for the coated sub-unit to obtain the coating thickness deviation value of the casting liquid for each non-stator unit.

[0034] The deviation value of the casting liquid coating thickness of each non-stator unit is multiplied by a preset deviation coefficient to obtain the deviation standard value of the non-stator unit.

[0035] The deviations from the standard values ​​of all non-stator elements are summed to obtain the total deviation from the standard values ​​of the non-stator elements.

[0036] Connect all non-stator units end to end to obtain the non-stator region of the non-stator unit;

[0037] The ratio of the non-stator area of ​​the non-stator unit to the area of ​​the carrier coated with casting liquid is then calculated to obtain the non-stator area ratio of the non-stator unit.

[0038] The extreme deviation value of the non-stator element is calculated by multiplying it by the non-stator area ratio of the non-stator element to obtain the regional deviation base value of the non-stator element.

[0039] The coating deviation base value is obtained by multiplying the regional deviation base value of the non-stator unit with the total deviation standard value of the non-stator unit.

[0040] As a further aspect of the present invention: the extreme deviation value of the non-stator unit is the difference between the maximum deviation value of the non-stator unit from the standard value and the minimum deviation value of the non-stator unit from the standard value.

[0041] As a further aspect of the present invention: the process of obtaining the coating behavior value is as follows:

[0042] The coating process of the film scraper on the carrier is divided into several time sub-units;

[0043] The coating speed of the scraper within the coating time is recorded as TS;

[0044] The coating pressure of the coating machine during the coating time is recorded as TY;

[0045] The coating speed TS and coating pressure TY of the coating machine during the coating time are weighted to obtain the coating behavior value.

[0046] As a further aspect of the present invention: the process of obtaining the coating speed of the film scraper within the coating time is as follows;

[0047] Obtain the maximum and minimum coating speeds of the internal coating machine in each time sub-unit;

[0048] Within a time sub-unit, the sum of the maximum and minimum coating speeds of the scraper and the average value are taken to obtain the actual coating speed of the time sub-unit.

[0049] The speed coating ratio of the time sub-unit is obtained by calculating the ratio of the actual coating speed of the time sub-unit to the actual coating speed threshold of the time sub-unit.

[0050] The coating speed of the scraper within the coating time is obtained by summing and averaging the coating ratios of all time sub-units.

[0051] The beneficial effects of this invention are as follows: This invention acquires the coating state data of the casting liquid on the carrier by dividing the area of ​​the carrier coated with the casting liquid into several coating sub-units. The coating thickness value of the casting liquid in each coating sub-unit is processed to obtain the coating consistency value. Then, the coating thickness value of the casting liquid in each non-stator unit is compared with the preset requirement of the coating thickness value of the coating sub-unit to obtain the coating thickness deviation value of the casting liquid in each non-stator unit. Combined with the non-stator unit's non-stator area on the carrier, a coating deviation base value is obtained. Finally, combined with the coating state of the scraper on the carrier, that is, obtaining the scraper's coating speed and coating pressure within the coating time, a coating behavior value is obtained based on the scraper's coating speed and coating pressure within the coating time. In other words, the coating quality of the casting liquid is monitored from multiple dimensions, with high accuracy and high reliability. Attached Figure Description

[0052] The invention will now be further described with reference to the accompanying drawings.

[0053] Figure 1 This is a flowchart of a membrane manufacturing method suitable for blood filtration according to an embodiment of the present invention;

[0054] Figure 2 This is a flowchart illustrating the coating quality identification process in a membrane manufacturing method applicable to blood filtration according to an embodiment of the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] Example 1

[0057] Please see Figures 1-2 As shown, the present invention is a membrane manufacturing method suitable for blood filtration, comprising the following steps:

[0058] Step 1: Dissolve the polysulfone-polyethylene glycol block copolymer in the casting solution solvent. After heating and mechanical stirring to dissolve, and allowing it to stand to degas, a well-dissolved and clear casting solution is obtained.

[0059] Step 2: The casting solution is uniformly coated onto the carrier using a coating machine. The coating status data of the casting solution is acquired, and the coating status value is obtained based on the coating status data.

[0060] The coating status value is compared with the preset coating status value requirement.

[0061] If the coating state value meets the preset requirements for coating state value, proceed to step three;

[0062] If the coating state value does not meet the preset requirements for coating state value, then continue to step two;

[0063] Step 3: Place the coating carrier into an oven and dry it to obtain a preliminary membrane. Then, heat-treat the preliminary membrane and further modify it to obtain a membrane for blood filtration.

[0064] In step one, the molecular weight of the polysulfone polyethylene glycol block copolymer is between 68-182 kDa; preferably between 95-96 kDa.

[0065] In the polysulfone-polyethylene glycol block copolymer, the mass ratio of polysulfone blocks to polyethylene glycol blocks is 3 to 4, preferably 3.7 to 3.8;

[0066] In step two, the vehicle includes, but is not limited to, a glass plate or a plastic plate;

[0067] In step three, the finishing process includes, but is not limited to, cutting, punching, and coating the heat-treated film.

[0068] In step two, the coating status data includes coating consistency value, coating deviation from baseline value, and coating behavior value;

[0069] The process of obtaining the coating contiguous value is as follows:

[0070] The area of ​​the carrier coated with the casting solution is divided into several coating sub-units according to its area;

[0071] Obtain the coating thickness value of the casting liquid for each coating subunit;

[0072] The process for obtaining the coating thickness value of the casting solution is as follows:

[0073] An inscribed circle is constructed within the coating sub-unit, and several thickness sampling points are collected at the center and circumference of the inscribed circle.

[0074] The thickness value corresponding to each thickness acquisition point is collected, and the obtained thickness values ​​are summed and averaged to obtain the coating thickness value of the casting liquid corresponding to each coating sub-unit.

[0075] The coating thickness values ​​of the casting liquid of all coating sub-units are integrated to obtain the coating thickness value group of the casting liquid of the coating sub-unit;

[0076] The coating thickness values ​​of the casting liquid in the coating subunit are processed according to the variance calculation formula to obtain the coating variance value of the casting liquid coating thickness value of the coating subunit.

[0077] The coating thickness value of the casting liquid in the coating sub-unit is compared with the preset requirement of the coating thickness value of the casting liquid in the coating sub-unit.

[0078] A coating subunit whose casting liquid coating thickness value meets the preset requirement of the casting liquid coating thickness value of the coating subunit is denoted as a calibration subunit;

[0079] A coating sub-unit whose casting liquid coating thickness value does not meet the preset requirement of the casting liquid coating thickness value of the coating sub-unit is recorded as a non-stator sub-unit;

[0080] Obtain the number of non-stator units, and calculate the ratio of the number of non-stator units to the number of coated sub-units to obtain the non-stator ratio of the coated sub-units;

[0081] The coating integral value is obtained by multiplying the non-fixed ratio of the coating sub-unit with the coating variance value of the casting liquid coating thickness value of the coating sub-unit.

[0082] The process of obtaining the coating deviation from the baseline value is as follows:

[0083] Obtain the coating thickness value of the casting liquid for each non-stator unit;

[0084] The coating thickness value of the casting liquid for each non-stator unit is compared with the preset requirement of the coating thickness value of the coating liquid for the coated sub-unit to obtain the coating thickness deviation value of the casting liquid for each non-stator unit.

[0085] The deviation value of the casting liquid coating thickness of each non-stator unit is multiplied by a preset deviation coefficient to obtain the deviation standard value of the non-stator unit.

[0086] The preset deviation coefficient is set by the staff based on experience. The larger the value of the preset deviation coefficient, the greater the adverse effect of the deviation of the non-stator unit from the standard value on the coating state.

[0087] The deviations from the standard values ​​of all non-stator elements are summed to obtain the total deviation from the standard values ​​of the non-stator elements.

[0088] The non-stator unit corresponding to the maximum deviation of the standard value of the non-stator unit is denoted as the first polarity unit;

[0089] The non-stator unit corresponding to the minimum deviation of the standard value of the non-stator unit is denoted as the second polarity unit;

[0090] The difference between the coating thickness of the casting solution of the first polarity unit and the coating thickness of the casting solution of the second polarity unit is calculated to obtain the polar deviation value of the non-stator unit.

[0091] Then connect all the non-stator units end to end to obtain the non-stator region of the non-stator unit;

[0092] Obtain the area of ​​the non-stator region of the non-stator unit, and then calculate the ratio of the area of ​​the non-stator region of the non-stator unit to the area of ​​the region coated with casting liquid on the carrier to obtain the non-stator area ratio of the non-stator unit;

[0093] The extreme deviation value of the non-stator element is calculated by multiplying it by the non-stator area ratio of the non-stator element to obtain the regional deviation base value of the non-stator element.

[0094] The coating deviation base value is obtained by multiplying the regional deviation base value of the non-stator unit with the total deviation standard value of the non-stator unit.

[0095] The process of obtaining the coating behavior value is as follows:

[0096] The coating process of the film scraper on the carrier is divided into several time sub-units;

[0097] The coating speed of the film scraper during the coating time is obtained;

[0098] Obtain the maximum and minimum coating speeds of the internal coating machine in each time sub-unit;

[0099] Within a time sub-unit, the sum of the maximum and minimum coating speeds of the scraper and the average value are taken to obtain the actual coating speed of the time sub-unit.

[0100] The speed coating ratio of the time sub-unit is obtained by calculating the ratio of the actual coating speed of the time sub-unit to the actual coating speed threshold of the time sub-unit.

[0101] The actual coating speed threshold for the time sub-unit is an empirical value.

[0102] The coating speed of the scraper within the coating time is obtained by summing and averaging the coating ratios of all time sub-units.

[0103] The coating pressure of the film scraper during the coating time is obtained;

[0104] Obtain the coating pressure value corresponding to the midpoint of each time sub-unit, and record it as the coating pressure value of the time sub-unit;

[0105] The pressure coating ratio of the time sub-unit is obtained by calculating the ratio of the coating pressure value of the time sub-unit to the coating pressure value threshold of the time sub-unit.

[0106] Among them, the coating pressure threshold of the time sub-unit is an empirical value;

[0107] The coating pressure of the scraper within the coating time is obtained by summing and averaging the pressure coating ratios of all time sub-units.

[0108] The coating speed of the film scraper during the coating time is denoted as TS;

[0109] The coating pressure of the coating machine during the coating time is denoted as TY;

[0110] The coating speed TS and coating pressure TY of the coating machine during the coating time are weighted and processed. The weight ratio of the coating speed TS during the coating time is assigned as n1, and the weight ratio of the coating pressure TY during the coating time is assigned as n2.

[0111] The coating behavior value TX is calculated using the formula TX=TS×n1+TY×n2, where n1 and n2 are both greater than zero, and n1+n2=1;

[0112] The coating continuity value is denoted as TL;

[0113] The deviation of the coating from the baseline value is denoted as TP;

[0114] That is, through the formula The coating state data is calculated to obtain the coating state value Ti, where a1, a2, and a3 are all preset proportional coefficients, and a1, a2, and a3 are all greater than zero.

[0115] The threshold value for obtaining the coating state value from the preset coating state data is ti. The coating state value Ti obtained from the coating state data is compared with the threshold value ti obtained from the coating state data.

[0116] If the coating state value Ti obtained from the coating state data is greater than or equal to the coating state value threshold ti obtained from the coating state data, it indicates that the coating quality of the casting liquid on the carrier is poor, and a second coating process is required.

[0117] If the coating state value Ti obtained from the coating state data is less than the coating state value threshold ti obtained from the coating state data, it indicates that the coating quality of the casting liquid on the carrier is good, and proceed to step three.

[0118] Example 2

[0119] A membrane manufactured using a membrane manufacturing method suitable for blood filtration.

[0120] The core of this invention lies in acquiring the coating status data of the casting solution on the carrier. Specifically, the area of ​​the carrier coated with the casting solution is divided into several coating sub-units. The coating thickness value of each sub-unit is processed to obtain a coating consistency value. Then, the coating thickness value of each non-stator unit is compared with a preset requirement to obtain a coating thickness deviation value for each non-stator unit. This deviation is combined with the non-stator area of ​​the non-stator unit on the carrier to obtain a coating deviation baseline value. Finally, the coating status of the scraper on the carrier is considered, specifically the scraper's coating speed and pressure within the coating time. Based on these parameters, a coating behavior value is obtained. This allows for monitoring of the casting solution coating quality from multiple dimensions, resulting in high accuracy and reliability.

[0121] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A method for manufacturing a membrane suitable for blood filtration, characterized in that, Includes the following steps: Step 1: Dissolve the polysulfone-polyethylene glycol block copolymer in the casting solution solvent. After heating and mechanical stirring to dissolve, and allowing it to stand to degas, a well-dissolved and clear casting solution is obtained. Step 2: The casting solution is uniformly coated onto the carrier using a coating machine. The coating status data of the casting solution is acquired, and the coating status value is obtained based on the coating status data. The coating status value is compared with the preset coating status value requirement. If the coating state value meets the preset requirements for coating state value, proceed to step three; If the coating state value does not meet the preset requirements for coating state value, then continue to step two; Step 3: Place the coating carrier into an oven and dry it to obtain a preliminary membrane. Then, heat-treat the preliminary membrane and further modify the treated membrane to obtain a membrane for blood filtration. In step two, the coating status data includes coating consistency value, coating deviation from baseline value, and coating behavior value; The coating continuity value is denoted as TL; The deviation of the coating from the baseline value is denoted as TP; The coating behavior value is denoted as TX; Through formula The coating state data is calculated to obtain the coating state value Ti, where a1, a2, and a3 are all preset scaling coefficients, and a1, a2, and a3 are all greater than zero; The process of obtaining the coating continuous value TL is as follows: The area of ​​the carrier coated with the casting solution is divided into several coating sub-units according to its area; Obtain the coating thickness value of the casting liquid for each coating subunit; The coating thickness values ​​of the casting liquid of all coating sub-units are integrated to obtain the coating thickness value group of the casting liquid of the coating sub-unit; The coating thickness values ​​of the casting liquid in the coating subunit are processed according to the variance calculation formula to obtain the coating variance value of the casting liquid coating thickness value of the coating subunit. The coating thickness value of the casting liquid of the coating sub-unit is compared with the preset requirement of the coating thickness value of the casting liquid of the coating sub-unit to obtain the calibration sub-unit and the non-stator unit; The ratio of the number of non-stator units to the number of coated sub-units is calculated to obtain the non-stator ratio of the coated sub-units. The coating integral value is obtained by multiplying the non-fixed ratio of the coating sub-unit with the coating variance value of the casting liquid coating thickness value of the coating sub-unit; The process for obtaining the coating deviation from the baseline value TP is as follows: Obtain the coating thickness value of the casting liquid for each non-stator unit; The coating thickness value of the casting liquid for each non-stator unit is compared with the preset requirement of the coating thickness value of the coating sub-unit to obtain the coating thickness deviation value of the casting liquid for each non-stator unit. The deviation value of the casting liquid coating thickness of each non-stator unit is multiplied by a preset deviation coefficient to obtain the deviation standard value of the non-stator unit. The deviations from the standard values ​​of all non-stator elements are summed to obtain the total deviation from the standard values ​​of the non-stator elements. Connect all non-stator units end to end to obtain the non-stator region of the non-stator unit; The ratio of the non-stator area of ​​the non-stator unit to the area of ​​the carrier coated with casting liquid is then calculated to obtain the non-stator area ratio of the non-stator unit. The extreme deviation value of the non-stator element is calculated by multiplying it by the non-stator area ratio of the non-stator element to obtain the regional deviation base value of the non-stator element; The coating deviation base value is obtained by multiplying the regional deviation base value of the non-stator unit with the total deviation standard value of the non-stator unit; The process of obtaining the coating behavior value TX is as follows: The coating process of the film scraper on the carrier is divided into several time sub-units; The coating speed of the scraper within the coating time is recorded as TS; The coating pressure of the coating machine during the coating time is recorded as TY; The coating speed TS and coating pressure TY of the coating machine during the coating time are weighted to obtain the coating behavior value.

2. The method for manufacturing a membrane suitable for blood filtration according to claim 1, characterized in that, The process for obtaining the coating thickness value of the casting solution is as follows: An inscribed circle is constructed within the coating sub-unit, and several thickness sampling points are collected at the center and circumference of the inscribed circle. The thickness value corresponding to each thickness acquisition point is collected, and the obtained thickness values ​​are summed and averaged to obtain the coating thickness value of the casting liquid corresponding to each coating sub-unit.

3. The method for manufacturing a membrane suitable for blood filtration according to claim 1, characterized in that, A coating subunit whose casting liquid coating thickness value meets the preset requirement of the casting liquid coating thickness value of the coating subunit is denoted as a calibration subunit; A coating sub-unit whose casting liquid coating thickness does not meet the preset requirement of the coating liquid coating thickness of the coating sub-unit is recorded as a non-stator sub-unit.

4. The method for manufacturing a membrane suitable for blood filtration according to claim 1, characterized in that, The extreme deviation value of the non-stator element is the difference between the maximum deviation of the non-stator element from the standard value and the minimum deviation of the non-stator element from the standard value.

5. A method for manufacturing a membrane suitable for blood filtration according to claim 1, characterized in that, The process of obtaining the coating speed of the coating machine within the coating time is as follows; Obtain the maximum and minimum coating speeds of the internal coating machine in each time sub-unit; Within a time sub-unit, the sum of the maximum and minimum coating speeds of the scraper and the average value are taken to obtain the actual coating speed of the time sub-unit. The speed coating ratio of the time sub-unit is obtained by calculating the ratio of the actual coating speed of the time sub-unit to the actual coating speed threshold of the time sub-unit. The coating speed of the scraper within the coating time is obtained by summing and averaging the coating ratios of all time sub-units.

6. A membrane suitable for blood filtration, characterized in that, It is manufactured by the method described in any one of claims 1-5.

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