The analysis of filtration accuracy of microporous membrane can be carried out from the following aspects:

1、 Basic characteristics of microporous membrane

Microporous membrane is a refined filtration material that can trap larger solid particles, microorganisms, and some bacteria in a solution, while solvents and small molecular substances can pass through the membrane. The basic principle is the screening process, which involves the separation of specific substances through microporous membrane materials under the action of static pressure difference in the raw material liquid. The pore size of the microporous membrane is very uniform, and the pore size is reasonably selected according to the substance to be separated, thereby ensuring high filtration accuracy.

2、 Definition and Range of Filtering Accuracy

Filtration accuracy refers to the minimum size of particles or molecules that can be retained by a microporous membrane. The pore size range of microporous membrane is wide, generally between 0.02-10 microns, and the specific pore size depends on the type and purpose of the membrane. For example, the filtration accuracy of ultrafiltration membranes is usually between 0.001 and 0.1 micrometers, while the filtration accuracy of nanofiltration membranes is even higher, generally below 0.001 micrometers.

3、 Factors affecting filtration accuracy

Aperture size: Aperture is a key factor determining filtration accuracy. The smaller the aperture, the smaller the particle or molecular size that can be intercepted, and the higher the filtration accuracy.

Membrane materials: Microporous membranes made of different materials have different chemical stability and physical properties, which can affect their filtration accuracy and service life. For example, polyvinylidene fluoride (PVDF) membranes have a wide range of temperature applications and good chemical stability, making them suitable for various environments; Nylon filter membranes have good temperature resistance and chemical stability, and are suitable for filtering aqueous solutions and most organic solvents.

Operating conditions: Operating pressure, temperature, flow rate, and other conditions can also affect the filtration accuracy of microporous membranes. Generally speaking, the higher the operating pressure, the higher the filtration accuracy may be, but it will also increase the membrane load and wear.

4、 Selection and Application of Filtering Accuracy

When selecting the filtration accuracy of a microporous membrane, multiple factors need to be considered comprehensively, including the size of particles or molecules in the medium to be filtered, the requirements of the filtration system, the material and chemical compatibility of the membrane, and cost-effectiveness. For example, in the fields of pharmaceutical manufacturing and food processing, there are higher requirements for filtration accuracy to ensure product quality and safety. It is usually recommended to use a 0.22-micron microporous membrane to filter out small particles and microorganisms. In the field of water treatment, for scenarios that require the removal of suspended particles, colloids, bacteria, and other impurities from water, ultrafiltration membranes can be chosen for filtration.

5、 Summary

The filtration accuracy of microporous membrane is one of its core performance indicators, which directly affects its filtration effect and service life. When selecting and using microporous membranes, it is necessary to fully understand their characteristics, influencing factors, and application scenarios to ensure that they can meet practical needs and achieve optimal performance. Meanwhile, with the continuous advancement of technology and the expansion of applications, the filtration accuracy of microporous membranes will also continue to improve and perfect.