How to Use and What are Use Notes of Filter Membrane?

Microporous membrane is mainly made of refined nitrocellulose, adding the appropriate amounts of cellulose acetate, acetone, n-butanol, ethanol, etc. It is hydrophilic, non-toxic, and hygienic. Penetrating micropores, the absolute pore size of the microporosity is as high as 80‰. The pore size is relatively uniform, the porosity is high, there is no medium shedding, the texture is thin, the resistance is small, the filtration speed is fast, and the adsorption is extremely small. It is flammable and should be sealed, moisture-proof and fire-proof when stored. Hawach provides Microporous Glass Fiber Membrane Filters, PVDF Membrane Filters, PES Membrane Filters, MCE Membrane Filters, and other membrane filter for your choice.

The filter membrane is simple and fast to use and is widely used in scientific research, food testing, the chemical industry, nanotechnology, energy, and environmental protection, and many other fields. It can be classified into different types based on different standards. From the perspective of material, it can be nylon, PTFE, PVDF, PP, MCE, PS, and so on. Different materials have different features and applications. For instance, PP (polypropylene stretched microporous membranes and polypropylene fibrous depth filtration membranes) membrane has good chemical stability and can be resistant to acid, alkali, and various organic solvents. cheap price.

However, this type of membrane has a wide pore size distribution. The current commercial membranes have various configurations of flat plate and hollow brazing. And different aperture specifications are available.

Polysulfone (PS) and Polyethersulfone (PES) microfiltration membranes have good chemical and thermal stability, radiation resistance, high mechanical strength, and wide application. Both PVDF and PTFE membranes are chemically stable and suitable for use at high temperatures. In particular, the PTFE membrane, which is used at a temperature of -40 to 260 °C, is resistant to strong acids, alkalis, and various organic solvents. Due to its hydrophobicity, it can be used to filter vapors and various corrosive liquids.

Three steps to use the filter membrane

1. Selection of microporous membrane. According to the solvent to be filtered, select the appropriate material and specification of the microporous filter membrane to open the package in the clean area. For example, if the solvent to be filtered is a strong acid or strong base, a microporous membrane made of PTFE is used.
2. Check the selected microporous membrane. Check pores, cracks, and foreign matter on the membranes carefully. Due to the improvement of the manufacturing process of the microporous membrane, the quality of the current microporous membrane, whether it is domestic or imported, is relatively good, and the above situation will not occur.
3. Immersion of microporous membrane. Rinse with distilled water several times before the microporous membrane, and soak it in water for injection for one day, so that the microporous membrane can achieve the best effect.

What are the details to be aware of when using membranes?

1. Before using the microporous filter membrane, the pore size of the membrane must be accurately selected according to the needs, and the substance to be filtered must be larger than the filter membrane pore sizes.
2. Before use, please confirm whether the microporous filter membrane is not resistant to acid and alkali, and is not resistant to solvents. Before use, you must know whether the filter material has an impact on the membrane.
3. Before use, it should be cleaned and soaked in water for injection at about 70°C for 1 hour.  Take it out for temporary use, rinse it with water for injection, and then put it into the filter for installation. When installing, please prevent the filter membrane from being installed crookedly and leaking. If the temperature is low, the treated filter membrane should be soaked in water for injection with the same temperature as the liquid for 5-10 minutes, which can avoid rupture caused by the tensile strength decrease because of the temperature difference.
4. When there are many particles and bacteria in the filtrate, it should be pre-filtered, that is, use pre-filter media or large-pore filter membrane to filter first to avoid too fast clogging.
5. 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.
6. If the microporous filter membrane is found to have small holes or small cracks, it can be rinsed with the unused filter membrane, dried, then shredded and placed in a small cup with a small amount of acetone, and stirred into a paste-like mucus. The mucus drips on the small holes or small cracks of the flat filter membrane.
7. After use, put the microporous membrane in water for injection to prevent drying, but do not soak it for too long.