3 Frequently Used Filter Membranes: Nylon, PES and PP

Nylon filter membrane

Nylon filter membrane is a natural hydrophilic organic polymeric microporous membrane with good temperature resistance (maximum working temperature 85℃ at 1.5 bar) and chemical stability, which can effectively filter all aqueous solutions and most organic solvents (such as alcohols, hydrocarbons, ethers, esters, ketones), and tolerate a variety of organic and inorganic compounds such as dilute acids and bases (acid-base tolerance range PH: 6-13). HAWACH Nylon filter membranes have a pore size range of 0.1-10um and thickness of 90-140 um, and are characterized by chemical stability, tear resistance, good mechanical strength (PET support layer), etc. A strict cleaning procedure results in extremely low membrane leachate and precise control of membrane pore size. Ensure effective filtration needs in each solvent.

Nylon membranes are widely used for three sectors:
1. Filtration for sterilization of laboratory samples
Pre-filtration of liquid chromatography and filtration of mobile phase
Microbiological laboratory applications
Filtration of micron-sized particles or colloids from laboratory water, organic solvents, and biological filtrates
Laboratory filtration of special solvents

2. Industrial applications
Removal of suspended substances and large colloids in water treatment
Ultra-pure water preparation for the microelectronics industry
Preparation of sterile water for food and beverage and brewing industries and removal of microorganisms and other impurities and odors

3. Pharmaceutical, plastic, biological, and other chemical industries: removal of impurities

PES filter membrane

Polyethersulfone (abbreviated as PES) is produced by the condensation of 4,4′-di sulfonyl diphenyl ether with diphenyl ether catalyzed by anhydrous ferric chloride. Heat resistance is between polysulfone and poly aryl sulfone, with a long-term use temperature of 180-200 ℃ and excellent aging resistance. PES is usually an amorphous polymer. Compared with polysulfone, PES has a higher heat resistance and rigidity.

PES membrane has good hydrophilicity and flux, is an absolute filtration material, can effectively retain particles larger than the absolute value of the membrane pore, is alkaline PH stable, has good chemical stability and inertness, high drug compatibility, and temperature stability performance. The whole membrane can be autoclaved and sterilized with guaranteed integrity, and maintains good shrinkage resistance of the membrane itself, reducing the occurrence of membrane tearing and flow rate reduction in the filter during use.PES membranes are widely used for filtration and clarification in food and pharmaceuticals and are also well suited for biological sample preparation due to their low protein adsorption properties. PES filter membranes are characterized by high flow rate, high throughput, autoclavable, non-adsorption of proteins and extracts, and non-contamination of samples. The pore size range can be 0.1μm, 0.22μm, 0.45μm, 0.65μm, 0.8μm, 1.2μm, etc.

PP filter membrane

Polypropylene (PP) is a semi-crystalline thermoplastic. It has high impact resistance, strong mechanical properties, and is resistant to many organic solvents and acid and alkali corrosion. It has a wide range of applications in industry and is one of the most common polymer materials. Australian coins are also made from polypropylene. PP filter membranes are made of polypropylene microfiber hot-melt bonded together and are a type of membrane material that belongs to deep filtration.

HAWACH produces PP filter membranes, which are hydrophobic microporous membranes with good chemical stability and good chemical compatibility in both aqueous and alcoholic solutions. They are suitable for high-performance liquid chromatography, gas separation, and the production of photoresist materials. It’s made of food-grade isogauge polypropylene, the whole production process is free of any additives; stable physical and chemical properties with good compatibility; with various series of pore sizes, high porosity, large dirt-holding capacity, back flushable and high-temperature disinfection; good pressure resistance. The available diameters are 13mm, 25mm, 47mm, 90mm, 142mm, and 293mm and available pore sizes are 0.1μm, 0.22μm, 0.45μm, 0.65μm, 0.8μm, 1.0μm, 3.0μm, 5.0μm and 10μm. The main applications include the filtration of aqueous and organic solutions; high-performance liquid chromatography sample filtration; ion exchange chromatography sample filtration; gas separation filtration.