The Following Helps You Have a Better Understanding of Microporous Membrane

The microporous membrane can be used in many industries. The common uses of the microporous membrane include separating the impurities, like the particles and bacteria from the gas or liquid phase. It can be used combined with filters, funnels, or syringe filters, which depends on what type of microporous membrane we are using. It would require corresponding clamps and pressure for larger diameter microporous membranes. There are two types of microfiltration operations: Deadend and Crossflow. For the Deadend operation, it can be used in smaller-scale applications or dilute (solid content) feed liquids. The filter membrane is made into a filter element, which is mostly disposable. The cross-flow operation, also known as tangential flow operation, is not very sensitive to changes in the size and concentration of suspended particles and is suitable for large-scale applications. Hawach has Microporous Glass Fiber Membrane Filters, PVDF Membrane Filters, Nylon Membrane Filters, PES Membrane Filters, MCE Membrane Filters, and other membrane filter for your choice.

Pore Size Applications

Pore sizeApplications
3.0-10.0μmSecurity filter before RO desalination
0.6-0.8μmFiltration of particles in large-dose injections and large infusions, filtration of beer and beverages, clarification and filtration of oil photoresist, spray paint solvents, etc.
0.45μmTerminal filtration of high-purity water in the electronics industry, filtration of MOS reagents
0.2μmSterilization filtration of medicinal liquids, biological preparations, and heat-sensitive fluids, terminal filtration of ultrapure water in the electronics industry, clarification filtration of low-alcohol wine
1-5μmTo filter larger particles of impurities, or for pretreatment of difficult to handle turbid solutions, it can be filtered with a 1-5μm filter membrane first and then filtered with the corresponding filter membrane.

Filtration Mechanism:

The filtration mechanism of microporous membranes involves sieving particles based on their size. Smaller particles that can fit through the pores pass through the membrane, while larger particles are retained. The efficiency of the filtration process is influenced by factors such as pore size, material composition, and operating conditions.

Hydrophilic and Hydrophobic Membranes:

Microporous membranes can be classified as hydrophilic or hydrophobic. Hydrophilic membranes attract water and are suitable for aqueous solutions, while hydrophobic membranes repel water and are useful for applications involving non-aqueous solutions or gases.

Microporous Membrane Selection

For your reference, the following table shows how to choose the microporous membrane.



Water-based membrane (mixed fiber resin) microporous membraneOil-based membrane (vinylidene fluoride resin film)Water and oil membrane (nylon membrane)
AcidsGlacial acetic acid, boric acid, hydrochloric acidAcetic acid concentrated hydrochloric acidAcetic acid
AlkaliSodium hydroxideSodium hydroxide3N sodium hydroxide
AlcoholsGlycerol, n-butanolMethanol, ethanolMethanol, ethanol, isopropanol, butanol, pentanol
AlkanesBenzene, toluene, petroleum ether, pentane, carbon tetroxideHexane, tolueneStupid, toluene, xylene
OtherPetroleum, silicone oil, gasoline, kerosene, distilled water, tap water, etc.Acetone, ether, chloroform, acetonitrile, tetrahydrofuran, silicone oil, freon, acetaldehyde, hydrogen peroxide, trichloroethylene, butyl acetate, etc.Ethyl acetate, butyl acetate, ether, chloroform, carbon tetrachloride, acetone, acetonitrile, distilled water formaldehyde, kerosene, glycerin
Features and precautionsBefore use, it should be soaked and washed with distilled water. The membrane is flammable, not resistant to acids and alkalis, and not resistant to solvents. It is only suitable for aqueous solutions (ph5-10)Before use, the filter membrane should be cleaned with an ethanol solution to rinse off the dust particles adsorbed on the surface of the filter membraneCan withstand a wide range of solvents, but when the filter residue is below 0.025 microns, it is not easy to use microporous membrane filtration
Disinfection methodGenerally, autoclave sterilization is used, that is, steam sterilization at 120°C for 30 minutes. During autoclave sterilization, avoid the direct one-way rush of steam on the membrane, and prevent the back of the membrane from being damaged by pressure due to the negative pressure generated by the steam condensation. Boiling disinfection, chemical disinfection, etc. are also available.

Use Process

The use process of microporous membrane:
(1) Cleaning frequency: Before the sterilization filtration operation, take a new microporous membrane and clean it once.
(2) Cleaning tools: clean container, tweezers.
(3) Cleaning method:

Method 1: Take the new product, rinse off the surface dust particles with purified water, and rinse with water for injection once; put the filter membrane in a container, add the appropriate amount of water for injection, immerse and boil for 30 minutes, and store it in a sealed container for later use.

Method 2: (1) Take a new filter membrane and soak it in water for injection at about 70°C for 1 hour.
(2) Replace with water for injection at about 40°C for 12 to 24 hours for later use.
(3) Rinse with fresh water for injection before use and then put it into the flat filter. After cleaning, put a “cleaned” status mark on the surface of the container.
(4) Evaluation of cleaning effect: tidy, clean, and free of foreign matter pollution.
(5) Cleaning tools should be cleaned and disinfected in accordance with the cleaning tool cleaning regulations.