A nanofiber membrane drainage capacity measuring device

Abstract

The utility model discloses a kind of nanofiber membrane drainage capacity measuring devices, including upper water tank, the upper water tank is used to store test water;The upper water tank is connected with vacuum device by test cavity;The test cavity is used to place nanofiber membrane to be detected;The upper water tank is connected with liquid level control instrument, the liquid level monitoring device is arranged in the upper water tank;The liquid level control instrument, the liquid level monitoring device, the vacuum device are electrically connected with control device;The liquid level control instrument, the liquid level monitoring device and the control device are used to keep constant pressure above nanofiber membrane to be detected;The vacuum device is used to keep constant pressure below nanofiber membrane to be detected, and collect water that permeates nanofiber membrane to be detected.The utility model not only can accurately determine the drainage capacity of hydrophobic nanofiber membrane, but also is suitable for hydrophilic nanofiber membrane, provides reliable basis for the performance evaluation of nanofiber membrane.

Description

Technical Field

[0001] This utility model relates to the field of medical device manufacturing technology, specifically to a device for measuring the drainage capacity of a nanofiber membrane. Background Technology

[0002] In the biomedical field, nanofiber membranes, as a highly promising material, have broad application prospects in wound dressings and tissue engineering. Their drainage capacity is crucial for maintaining a favorable physiological environment and promoting wound healing. For example, in wound dressing applications, timely and effective drainage of wound exudate can avoid the risk of infection caused by fluid accumulation, creating favorable conditions for wound healing. Accurately measuring the drainage capacity of nanofiber membranes is of great significance for evaluating their performance in practical applications, screening suitable materials, and further optimizing product design.

[0003] However, current methods for determining the drainage capacity of nanofiber membranes have several limitations. Some existing conventional methods struggle to accurately simulate the complex conditions of real-world applications, leading to significant discrepancies between the measured results and actual usage. Others are ineffective for hydrophobic nanofiber membranes, as their repulsive properties render traditional hydrophilic-based methods ineffective. For example, the method in GB / T 10340-2008, "Determination of Filtration Velocity of Paper and Paperboard," based on a Hertzberg filtration rate meter, is only suitable for hydrophilic samples. However, most nanofiber membrane dressings used in biomedicine are hydrophobic, and under single pressure conditions, water is unlikely to permeate these membranes, making their drainage capacity unmeasurable. Furthermore, existing methods use 50 and 100 mL of water permeation as quantitative standards, but hydrophobic nanofiber membranes have slower water permeation rates than filter paper or may not allow water to pass through at all. This quantitative approach is unsuitable for determining the drainage capacity of hydrophobic nanofiber membranes and requires targeted improvements. Furthermore, there are no quantitative indicators for the drainage capacity of hydrophilic nanofiber membranes. For example, current standards for breathable dressings (such as YY / T 0471.2-2004) only specify water vapor transmission rate (WVTR), with units of g / (m). 2 •24h). No quantitative indicators for drainage capacity are specified, which cannot meet current usage requirements.

[0004] Furthermore, after searching, it was found that there is no dedicated equipment for testing the drainage capacity of nanofiber membranes in the existing technology. Therefore, it is necessary to develop such equipment to solve the above-mentioned technical problems. Utility Model Content

[0005] To address the aforementioned issues, this invention provides a device for measuring the drainage capacity of nanofiber membranes. This device can accurately measure the drainage capacity of hydrophobic nanofiber membranes as well as hydrophilic nanofiber membranes, providing a reliable basis for the performance evaluation of nanofiber membranes. It is applicable to various types of nanofiber membranes and helps promote the application and development of nanofiber membranes in the biomedical field.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a device for measuring the drainage capacity of a nanofiber membrane, comprising an upper water tank for storing test water; the upper water tank being connected to a vacuum device via a test chamber; the test chamber being used to place the nanofiber membrane to be tested; the upper water tank being connected to a level controller, and a level monitoring device being installed inside the upper water tank; the level controller, the level monitoring device, the vacuum device, and a control device being electrically connected; the level controller, the level monitoring device, and the control device being used to control the test water in the upper water tank at a constant water level, thereby maintaining a constant pressure above the nanofiber membrane to be tested; the vacuum device being used to maintain a constant pressure below the nanofiber membrane to be tested and to collect water that permeates through the nanofiber membrane to be tested.

[0007] As a preferred technical solution of this utility model, the liquid level monitoring device is an ultrasonic liquid level monitor.

[0008] As a preferred technical solution of this utility model: the vacuum device includes a vacuum chamber, which is connected to the upper water tank through the test cavity; the vacuum chamber is connected to a vacuum pump; and the vacuum pump is electrically connected to the control device.

[0009] As a preferred technical solution of this utility model: a weight transmitter is provided at the bottom of the vacuum chamber, a measuring cylinder is provided above the weight transmitter, and the weight transmitter is electrically connected to the weight display screen.

[0010] As a preferred technical solution of this utility model: the vacuum chamber includes a chamber body and a bottom plate, the weight transmitter is disposed on the bottom plate, and the bottom plate is hinged to the lower part of the chamber body.

[0011] As a preferred technical solution of this utility model: the test chamber includes an upper clamp and a lower clamp, the upper clamp and the lower clamp cooperate with each other to clamp the nanofiber membrane to be tested; clamps are provided on the outer side of the upper clamp and the lower clamp.

[0012] This utility model has the following beneficial effects:

[0013] 1. It can not only accurately measure the liquid drainage capacity of hydrophobic nanofiber membranes, but is also applicable to hydrophilic nanofiber membranes, providing a reliable basis for the performance evaluation of nanofiber membranes. It can be applied to various types of nanofiber membranes, which helps to promote the application and development of nanofiber membranes in the biomedical field.

[0014] 2. It can perform fully automatic measurements, ensuring the accuracy and reproducibility of the measurement data. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the structure of the water tank, test chamber, and vacuum device of this utility model;

[0017] Figure 3 This is a schematic diagram of the overall structure of the upper clip;

[0018] Figure 4 This is a schematic diagram of the overall structure of the lower clip;

[0019] Figures 1-4 In the middle, 1. Upper water tank; 2. Test chamber; 3. Vacuum device; 4. Liquid level controller; 5. Liquid level monitoring device; 6. Vacuum chamber; 7. Vacuum pump; 8. Weight transmitter; 9. Measuring cylinder; 10. Weight display screen; 11. Chamber body; 12. Base plate; 13. Upper clamping plate; 14. Lower clamping plate; 15. Fixture; 16. First connecting pipe; 17. Second connecting pipe. Detailed Implementation

[0020] To make the objectives and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0021] like Figures 1-2As shown in the figure, this utility model embodiment provides a device for measuring the drainage capacity of nanofiber membranes, including an upper water tank 1 for storing test water; the upper water tank 1 is connected to a vacuum device 3 via a test chamber 2; the test chamber 2 is used to place the nanofiber membrane to be tested; the upper water tank 1 is connected to a level controller 4, and a level monitoring device 5 is installed inside the upper water tank 1. The level controller 4, the level monitoring device 5, the vacuum device 3, and the control device are electrically connected. The level monitoring device 5 detects the water level in the upper water tank 1. Based on the water level signal detected by the level monitoring device 5, the control device uses the level controller 4 to ensure that the test water in the upper water tank 1 is at a constant level, thus maintaining a constant pressure above the nanofiber membrane to be tested. The vacuum device 3, in conjunction with the control device, maintains a constant pressure below the nanofiber membrane to be tested and collects the water that permeates through the nanofiber membrane. The upper water tank 1 provides positive pressure to the nanofiber membrane under test, while the vacuum device 3 provides negative pressure. This creates a dual pressure difference, forming a vertical pressure channel of "positive pressure-membrane-negative pressure." This dual pressure difference provides sufficient force for water to permeate through the hydrophobic membrane within the test chamber 2, overcoming the limitation of national standard methods restricting the use of hydrophilic materials. This method can test not only the water permeability of hydrophobic nanofiber membranes but also that of hydrophilic nanofiber membranes, providing a reliable basis for the performance evaluation of nanofiber membranes.

[0022] The lower end of the upper water tank 1 is connected to the level controller 4 via a first connecting pipe 16. The control device is located inside the level controller 4. The level monitoring device 5 is either a radar level monitor or an ultrasonic level monitor, preferably an ultrasonic level monitor. The ultrasonic level monitor monitors the liquid level in the upper water tank 1 in real time and works in conjunction with the level controller 4. The level controller 4 dynamically adjusts the water inflow into the upper water tank 1 based on the data from the ultrasonic level monitor to maintain a constant water level, thus creating a stable positive pressure to provide positive pressure for water to permeate through the nanofiber membrane to be tested. In this embodiment, a water level of 200 mL is preferred, which provides a positive pressure of 1000 Pa for the nanofiber membrane to be tested.

[0023] The vacuum device 3 includes a vacuum chamber 6, which is connected to the upper water tank 1 via a test chamber 2. The vacuum chamber 6 is connected to a vacuum pump 7 via a second connecting pipe 17. The vacuum pump 7 is electrically connected to a control device. The vacuum chamber 6 acts as a negative pressure chamber, and the vacuum pump 7 is used to extract air from the vacuum chamber 6. By adjusting the pressure relief valve, the absolute pressure inside the vacuum chamber 6 is stabilized at a constant value, forming a stable negative pressure environment. In this embodiment, the constant absolute pressure is preferably 2000 Pa, which, together with the positive pressure of the upper water tank 1, forms a dual pressure difference. That is, in this embodiment, water can be driven to permeate the nanofiber membrane to be tested at a pressure of 3000 Pa. To facilitate the measurement of the liquid permeating the nanofiber membrane, a weight transmitter 8 is installed at the bottom of the vacuum chamber 6, and a measuring cylinder 9 is installed above the weight transmitter 8. The measuring cylinder 9 is used to collect the water permeating the nanofiber membrane. The weight transmitter 8 is electrically connected to a weight display screen 10. The weight transmitter 8 converts the weight of the water collected in the measuring cylinder 9 into an electrical signal, preferably with an accuracy of 0.001 g. In this embodiment, the weight display screen 10 is preferably mounted on the outer shell of the vacuum chamber 6 for easy observation. The vacuum chamber 6 includes a chamber body 11 and a base plate 12. To facilitate the placement and removal of the measuring cylinder 9, the weight transmitter 8 is mounted on the base plate 12, which is hinged to the lower part of the chamber body 11.

[0024] Combination Figure 1 , Figure 3 , Figure 4 As shown, the test chamber 2 includes an upper clamp 13 and a lower clamp 14, which cooperate to clamp the nanofiber membrane to be tested. A clamp 15 is provided on the outer side of the upper clamp 13 and the lower clamp 14. The upper clamp 13 and the lower clamp 14 cooperate to clamp the nanofiber membrane sample to be tested, ensuring the sample is flat and sealed, preventing pressure leakage. The lower clamp 14 and the upper clamp 13 together fix the nanofiber membrane to be tested, forming the test chamber 2, while allowing water permeable to the membrane to flow into the vacuum chamber 6 below. The clamp 15 is used to fasten the upper and lower clamps 14 and the connection between the water tank and the vacuum chamber 6, ensuring the airtightness of the entire test system and avoiding pressure loss.

[0025] The control device is a PLC device based on existing technology. Its control interface can display the real-time water level in water tank 1, the measurement time, and the vacuum degree in vacuum chamber 6. The "Calculation" program can calculate the water flow per unit area per unit time. After the preset measurement time is completed, the program automatically calculates and displays the water flow per unit area per unit time.

[0026] The working principle of this specific implementation is as follows: The nanofiber membrane sample to be tested is placed flat between the upper clamp 13 and the lower clamp 14 and fixed and sealed with clamp 15. The control device, ultrasonic level monitor, and level controller 4 fix the liquid level in the upper water tank 1 to 200mL, and the water temperature is preferably controlled at 23±1℃, so that the water pressure in the upper water tank 1 is fixed at 1000pa. Then, the vacuum pump 7 is started and the pressure relief valve is adjusted to maintain an absolute pressure of 2000Pa in the vacuum chamber 6, and the timing test begins. At this time, the water permeates through the nanofiber membrane to be tested under the pressure of the upper water tank 1 and the vacuum chamber 6 and is collected in the measuring cylinder 9. After the set filtration time is reached, the test is stopped and the volume weight G of the collected water is read from the weight display screen 10. The preferred filtration time in this implementation is 5h. The water flux is calculated by the formula J=G÷(A*t) preset by the control device program, where J is the water flux in g / (m³). 2 ·h); G is the mass of filtered water in grams (g), and A is the effective filtration area in square meters (m²). 2 t represents the filtration time in hours (h). After the test, the vacuum pump 7 must be turned off first, and the pressure slowly released before disassembling the device. During the process, it is important to maintain a constant ambient temperature and ensure that there are no leaks in any sealing links. If the test time is adjusted, the time parameter in the calculation formula must be modified accordingly. By unifying the drainage capacity to the same dimension, a direct comparison with the air permeability of dressings can be achieved, providing a method for the functional evaluation of hydrophobic materials.

[0027] The original standard's determination method, which used a fixed water permeability (50 / 100mL) as the endpoint, has been changed. Addressing the characteristics of hydrophobic membranes being impermeable or having a slow permeability rate, the method now uses time as the quantitative measure. It measures the weight of the permeated water within a specified time period. Compared to the water level reading method in "GB / T10340-2008 Determination of Filtration Velocity of Paper and Paperboard," this method directly measures the water permeability within a specified time period by weighing the permeate liquid using a high-precision weight transmitter 8. The water flux is then calculated using the preset formula J=G / (A×t) of the automatic calculation system. This solves the problem of large errors in hydrophobic membrane testing caused by the traditional water level reading method. Automated data acquisition avoids human error, providing a reliable, accurate, and repeatable testing solution for evaluating the performance of hydrophobic membrane materials.

[0028] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A nanofiber membrane drainage capacity measurement device, characterized by: The system includes an upper water tank (1) for storing test water; the upper water tank (1) is connected to a vacuum device (3) via a test chamber (2); the test chamber (2) is used to place the nanofiber membrane to be tested; the upper water tank (1) is connected to a level controller (4), and a level monitoring device (5) is installed inside the upper water tank (1); the level controller (4), the level monitoring device (5), the vacuum device (3) are electrically connected to a control device; the level controller (4), the level monitoring device (5) and the control device are used to control the test water in the upper water tank (1) at a constant water level, so that the pressure above the nanofiber membrane to be tested is kept constant; the vacuum device (3) is used to keep the pressure below the nanofiber membrane to be tested constant and to collect the water that permeates through the nanofiber membrane to be tested.

2. The nanofiber membrane drainage capacity measuring device according to claim 1, characterized in that: The liquid level monitoring device (5) is an ultrasonic liquid level monitor.

3. The device for measuring the drainage capacity of a nanofiber membrane according to claim 1, characterized in that: The vacuum device (3) includes a vacuum chamber (6), which is connected to the upper water tank (1) through the test chamber (2); the vacuum chamber (6) is connected to a vacuum pump (7); and the vacuum pump (7) is electrically connected to the control device.

4. The device for measuring the drainage capacity of a nanofiber membrane according to claim 3, characterized in that: A weight transmitter (8) is provided at the bottom of the vacuum chamber (6), and a measuring cylinder (9) is provided above the weight transmitter (8). The weight transmitter (8) is electrically connected to the weight display screen (10).

5. The device for measuring the drainage capacity of a nanofiber membrane according to claim 4, characterized in that: The vacuum chamber (6) includes a chamber body (11) and a base plate (12). The weight transmitter (8) is mounted on the base plate (12), which is hinged to the lower part of the chamber body (11).

6. The device for measuring the liquid drainage capacity of a nanofiber membrane according to any one of claims 1-5, characterized in that: The test chamber (2) includes an upper clamp (13) and a lower clamp (14), which cooperate with each other to clamp the nanofiber membrane to be tested; clamps (15) are provided on the outside of the upper clamp (13) and the lower clamp (14).

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