Characteristics and Applications of Several Commonly Used Filter Membranes

The membrane filter can be described as permeate and retentate when the substances pass a single feed stream through a membrane system and separate into two individual streams. And the membrane that separates them is acting like a physical barrier with highly specialized characteristics and pores so that only certain selected components in the stream can pass through while the larger particles are rejected on the surface and do not have a chance to go into the interior of the filter.

Membrane filter or is limited to membranes used to remove particles larger than 0.1 μm in diameter. The pores of membrane material are very small, so we need to drive force, pressuring the components to go through a thin layer of semi-permeable material.

With a full range of pore sizes and materials, Hawach has two types of membrane filters: round disc membrane filters and roll-type membrane filters. Both of them can be used for filtration and sterilization of liquids, gas, and other samples, removing all microorganisms and particles without any effects on the ingredients during the process.

Facing the enhancement of green, low-carbon, and environmental protection concepts in today’s world, HAWACH explores the development trend of chromatographic filtration and biological filtration with an international perspective, who is committed to developing high-end filtration products, introducing world-leading advanced production technology and manufacturing processes to meet customer high requirements.

Its filter membranes feature low impurity content with uniform material; 10W class clean workshop cutting and packing high cleanliness, no impurities introduced; ISO9001 standard specifications, strict product quality control, and good stability between different batches of the product. Its membranes have different diameters, and rolls have multiple widths for customers with different needs to choose from. There are many types of membrane materials, suitable for most laboratory samples of different fields, solvent filtration, and sterilization of solvents.

Here are the commonly used filter membranes.
1. Water-based membrane (mixed cellulose ester CN-CA)
Characteristics: Uniform pore size, high porosity, no medium shedding, thin texture, small resistance, fast filtration speed, low cost, but not resistant to organic solutions, and strong acids and alkalis.

Applications: Drinking water, surface water, well water, etc., sterilization filtration, analysis of particles and oil insoluble in solution, determination of water pollution index, filtration of particles and bacteria such as gas, oil, beverage, wine, etc. It is one of the most widely used filter membranes in sample pretreatment filtration.

2. Nylon membrane (polyamide NYLON)
Characteristics: Good temperature resistance, can withstand 121℃, saturated steam autoclaving for 30 minutes, a high operating temperature of 60℃, good chemical stability, resistance to various organic and inorganic compounds and solvents such as dilute acid and alkali.

Applications: Suitable for water filtration in electronics, microelectronics, semiconductor industry, tissue culture medium, medicinal solution, beverage, high-purity chemical, water, and organic solution mobile phase.

3. PVDF membrane (polyvinylidene fluoride)
Characteristics: The membrane has high mechanical strength, good tensile strength, good heat resistance and chemical stability, extremely low protein adsorption, and strong hydrophobicity.

Applications: Gas and steam filtration, high-temperature liquid filtration, sterilization filtration of tissue culture media, additives, etc., solvent and chemical raw material purification filtration.

4. PTFE (polytetrafluoroethylene)
Characteristics: It has a wide range of chemical compatibility, good temperature resistance, strong acid, and alkali resistance, strong chemically corrosive solvents, and oxidants.

Applications: Chemical, pharmaceutical, environmental protection, electronics, food, energy, and other fields. It can filter almost all organic solutions.