Introduction of Hawach Microporous Filter Membrane

For microfiltration, the membrane interception characteristics are characterized by the pore size, usually ranging from 0.1 microns to 1 micron, it can be used for clarification, security filtration, and air sterilization of general liquid. Microporous filter membrane is widely used in scientific research, medicine and health, biochemistry, food, energy, microelectronics industry, nanotechnology, environmental protection, and other departments.

The microporous filter is one of the most widely used membrane types in membrane separation technology. Microporous membrane filter has the characteristics of large gas flux, high particle retention rate, good temperature resistance, strong acid, strong alkali, organic solvent and oxidant, anti-aging and non-stick, non-flammable, non-toxic, and good biocompatibility. Microporous membrane material can be divided into organic and inorganic categories.

In view of the separation characteristics of the microporous filter, the application scope of the microporous membrane filter is mainly to trap particles, bacteria, and other pollutants in the gas phase and liquid phase to achieve the purpose of purification, separation, and concentration.

The Definition of Membrane Filter

The membrane water treatment is a solid-liquid separation technology. It is a technology that filters water through a membrane pore to trap impurities in the water without chemical changes and is easy to handle. However, due to the very small pore size, there are certain technical problems. A method of treating raw water with a biofilm is also used in the feed water, but it is different from the filtration membrane separation technique. The membrane used for membrane separation is called membrane, while the membrane used for biofilm treatment is called membrane.
At present, the membrane filter is applied to separate or enrich solutes in solution and it can also separate colloidal suspensions. Its application field is constantly expanding.

The Working principle of Membrane Filter

It filters particles larger than the aperture on its surface.

The Classification of Membrane Filter

The classification principle of the Hawach membrane filter is set by the size of particles retained in raw water. There are four kinds of membrane holes in Hawach Scientific membrane filters: microfiltration filters (MF), ultrafiltration filters (UF), nanofiltration filters (NF) and reverse osmosis filters (RO).

The pore size of MF membranes is over 0.05um or more than 1000 molecular weights. And the membranes are to remove colloids and macromolecule organic compounds.

The molecular weight of NF membranes’ pore size ranges from 100 to 1000. The membrane removes substances between UF and RO. These substances include trihalomethane, odor, chroma, pesticides, soluble organic matter, Ca, Mg, and so on.

As for the RO membranes, their particle size is 10 moles. This membrane is mainly to remove salt and inorganic salt in the separation process.

Application of Membrane Filter

The microporous filter membrane is mainly used for the filtration of the mobile phase and sample in chromatographic analysis. The microporous filter has a good effect on protecting the chromatographic column, infusion pump pipe system, and injection valve from contamination.

hydrophilic ptfe membrane filter

Material of Membrane Filter

1. MCE gridded membrane filter
2. Nylon membrane filter
3. PTFE membrane filter
4. PES membrane filter
5. CA membrane filter
6. PVDF membrane filter
7. GF membrane filter
8. PP membrane filter

Precautions when using membrane products

The determination of the bubble point: the determination of the bubble point pressure can reflect the pore size of the microporous membrane filter, which is closely related to the quality of the filtered microporous filter membrane solution and is also a kind of important means to guarantee the quality of the membrane.

The membrane used should be immersed in water for injection at 70 ° C for 1 h. Pour out the water and soak it in warm water for a night. Take it out when it is used, rinse it with water for injection, and put it into the filter for installation. Prevent the membrane from leaking.

To protect the service life of the filter, you can use the same size filter paper or crepe cloth (you should first boil the crepe cloth with a mass concentration of 20 g·L -1 sodium sulfonate solution for about 30 min, then clean it with water for injection). Place on the filter to prevent the filter from rupturing.

The pore size of the microporous membrane is cone-shaped, the smooth side has a small aperture for the front side; the rough side has a large aperture for the reverse side. When installing, the front side (glossy side) should face up and the reverse side (dark side) face down, otherwise, it is easy to be blocked by impurities and affects the filtration rate. When the temperature is low, the treated filter membrane should be immersed in the water for injection at the same temperature as the liquid medicine for 5 to 10 minutes to avoid cracking caused by the decrease of the tensile strength of the filter due to the temperature difference.

On the leather tube head of the exhaust pipe of the filter holder, fix a 16-gauge infusion needle and control it with a water stop clamp to avoid the rupture of the filter membrane due to excessive discharge pressure and speed.

When infusion filtration is first used in the multi-stage filtration device after coarse filtration and fine filtration, the microfiltration membrane can be used as the final fine filtration, and the pressure, decompression, and azimuth static filtration methods should be adopted.

Do not sterilize the filter holder together with the filter membrane. Otherwise, the filter membrane will be brittle and wrinkled due to thermal expansion and contraction. After use, the membrane is placed in water for injection to prevent drying but does not soak for too long. Do not use the microporous membrane that has been dehydrated and dried. Depending on the concentration and viscosity of the liquid, microporous membranes with different pore sizes should be used.

If the membrane is found to have small holes or small cracks, it can be rinsed with the original filter membrane and dried, then shredded into a small cup of acetone and stirred into a paste of mucus. Drop the small holes or small cracks in the flat membrane. It should not be too much. The mucus should be covered and slightly larger. After drying, it can be used without affecting.

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