Types and Applications of Filter Membranes

The membrane filter is widely used in today’s life, including ultrafiltration membranes, microporous membranes, nanofiltration membranes, microfiltration membranes, and mesoporous fiber ultrafiltration membranes, among others.

Types of Filter Membrane

In terms of shape, filter membranes are usually divided into two types: disc membranes and roll membranes.

1. Roll filter membrane

Hawach can supply a variety of raw materials for different materials to meet and adapt to the differentiated needs of production membrane manufacturers. The rolling membrane is rectangularly rolled together and is indicated by the width, with 254mm, 260mm, 270mm, 280mm, and 310 mm available. The inner core is 22mm.

2. Disc filter membrane

The disc membrane filter that HAWACH can provide diameter is 13mm to 293mm, the hole diameter is 0.1μm to 10μm, etc., and other specifications of the membrane can be customized according to the needs of users.

Applications

The membrane filter is used for food, beverage, medical, municipal water treatment, industrial high-purity water, boiler water, seawater desalination, electronic industry ultra-pure water, wastewater treatment and reuse, material concentration and purification, and other industries.

Click here to know more about PVDF vs PTFE. PTFE membrane is divided into the hydrophobic PTFE membrane and hydrophilic PTFE membrane, please click “Main Applications Of Hydrophobic and Hydrophilic PTFE Membrane Filter” to know more about it.

1. PP

The PP filter membrane has acid and alkali resistance, abrasion resistance, impact resistance, uniform micropore distribution, large filtration area, and good water permeability. Widely used in injection cleaning, medicinal liquid, medicinal wine, oral liquid, beverage, daily water, wastewater, air filtration, etc.

2. Glass Fiber(GF)

Due to the fiber material of the glass fiber membrane, it is not easy to clog, so it can provide excellent prefiltration functions for a series of filtration workflows. From basic liquid filtration to highly specialized gas and air filtration, it’s all covered. These properties also make it excellent as a direct filter for a buffer, reagent, and protein solution clarification, as well as for gravimetric analysis, air monitoring, and wastewater analysis. The 100% borosilicate structure of the glass fiber membrane not only gives it a pure white appearance, but compared with standard cellulose membranes, even with continuous use, there will be no performance degradation due to increased filtration load.

3. Cellulose Acetate(CA)

Cellulose acetate(CA) filter membrane is mainly used for daily air pollution monitoring and special monitoring of solid pollutants, microorganisms, oil, and acid mist in the air, efficient collection of fine particles, and water pollution analysis. It is an ideal product for collecting smoke and dust in the air and measuring it accurately. It is used to pre-filter the membrane to prevent clogging. Large surface area uses glass fiber membranes for excellent retention.

4. Polyethersulfone(PES)

In addition to the wide range of applications in the pharmaceutical and biotechnology industries, PES membranes filter are also suitable for other fields such as medical, food, and beverage drinking water, microelectronics, fine chemicals, etc.

In the application of membrane separation technology, the microporous membrane is the most widely used membrane type. What would be introduced below is the PES filter membrane, which is easy to use and is widely used in lots of fields, including scientific research, food detection, chemical, and environmental protection

The PES filter membrane is made of pure polyethersulfone and contains no supporting material. Due to its asymmetric structure, it has a high flow rate and superior throughput and can effectively remove particulate matter. Also, it possesses good mechanical strength, thermal stability, and extensive chemical compatibility. It could withstand high temperatures and greatly resist acid and alkaline samples. Moreover, it has low biosorption, which indicates that the proteins are not easy to bind together.

The PES filter membrane is suitable for filtration in the medicine industry, wastewater treatment, and drinking water purification. To be specific, it could be used for the filtration of pharmaceutical liquids, such as the filtration of biological and serum in the pharmaceutical industry, and terminal filtration of large infusion antibiotics. Besides, it is perfectly usable for the sterilization of tissue culture media, additives, buffers, and other aqueous solutions. It is also widely applied in terminal filtration in the food industry.

5. Nylon

The nylon filter membrane material is aliphatic nylon, which has good hydrophilicity and resistance to acid and alkali of the appropriate concentration. It is not only suitable for aqueous solutions containing acid and alkali, but also for organic solvents, such as alcohols, hydrocarbons, ethers, esters, ketones, homologs of benzene, and benzene, dimethyl formamide, and dimethyl sulfoxide, etc., are some of the most widely applicable microporous membranes. (Belonging to the terminal filter membrane).

Hawach membrane filter is made of high-purity grade nylon membranes for use in filtration when high purity and efficient particle removal are required. The intrinsically hydrophilic nature of nylon membranes allows for easy wetting across the membrane. Hydrophilic nylon membrane and pure polypropylene construction supply excellent chemical compatibility and a wide range of applications.

6. Polyvinylidene fluoride(PVDF)

For the PVDF filter, as the pore size of the membrane continues to decrease, the membrane binds to low molecular weight proteins more firmly. The use of the PVDF membrane requires pretreatment. The purpose of treatment with methanol is to activate the positively charged groups on the membrane and make it easier to bind to negatively charged proteins.

The Polyvinylidene fluoride membrane, often referred to as the PVDF membrane, is an ideal solid-phase support material commonly used in the Western Blot method. It is a hydrophobic filter membrane, which can be changed to a hydrophilic membrane after the alcohol treatment process. It needs to be pretreated with methanol before use.

The first and most noticeable feature of the PVDF membrane is its ultra-high mechanical strength, which ensures the membrane will not be easily damaged during the filtration. Also, its excellent chemical compatibility gives it a high tolerance for corrosive samples, oxidants, strong acids, and alkalis.

Compared with other membranes, its high flow rate allows it to filter the samples more efficiently. The ultra-low protein adsorption feature makes it quite suitable for liquid sterilization that contains biological components for higher protein recovery. It is also easy for the PVDF membrane to be mixed with other organic or inorganic materials to produce a better composite membrane.

Considering all the features, the PVDF membrane could play a significant role by being broadly applied in the biological field. It could also be used for the pretreatment of sewage and seawater desalination by efficiently removing impurities such as bacteria and sediment. Like all the other membranes, there are lots of sizes provided on the market.

PVDF membrane filters feature superior corrosion resistance, making them suitable for filtration of solutions containing solvents and acids. Both hydrophobic and modified-hydrophobic are of superior temperature tolerance and anti-pollution properties. It is the best choice for the filtration of organic solvents and additives, ultimate filtration of ink, filtration of solvents and chemical materials, and so on.

7. Nitro Cellulose

NC membranes are used in Northern Blot, Southern Blot, and Western Blot. Hybridization techniques are divided into solid-phase hybridization and liquid-phase hybridization. The solid-phase hybridization technology is currently more commonly used. The nucleic acid to be tested is first bound to a certain solid-phase support and then hybridized with the labeled probe in the liquid phase. The solid support is usually the nitrocellulose membrane.

8. Mixed Cellulose Esters(MCE)

The MCE filter membrane has a relatively uniform pore size, high porosity, no media shedding, thin texture, low resistance, fast filtration speed, minimal adsorption, and low cost, but it is not resistant to strong acid & alkali solutions and organic solutions.

9. Polytetrafluoroethylene(PTFE)

The PTFE filter membrane is made of PTFE, through a special process, two-way stretching, using the unique node fibril properties of the PTFE film, smooth surface, chemical resistance, air and water impermeability, large air permeability, flame retardant, and high-temperature resistance. The product is resistant to strong acids and alkalis, non-toxic, etc., with high filtration efficiency, up to 99.99%, near-zero emission, low running resistance, fast filtration speed, long service life, and reusable, thereby reducing operating costs.

PTFE membrane filter is naturally hydrophobic with good chemical tolerance, which is suitable for applications involving aggressive organic solvents, strong acids, and alkalis. It is optimized for low drug and protein with excellent performance throughout in typical aqueous and solvent sample preparation. High sample recovery and low extractability are available in the optimum analysis by HPLC and LC. Additionally, it is suitable for applications including natural product screening, aqueous solubility testing, and so on.

10. Hydrophilic PTFE

Hydrophilic PTFE filter membrane has wide applications, like the flue gas filtration of various industrial furnaces, for instance, the chemical industry, metallurgy,  power generation, cement, etc.

Hawach filter membranes have two types: round disc membrane filters and roll-type ones. They can be used for filtration and sterilization of liquids, gases, and other samples.

Working Principle

Known as surface filtration, membrane filtration is a process in which solid particles can be separated through a very thin filter medium. The particles are usually larger than the pore size of the membrane.

During separation, a semi-permeable membrane acts as a selective barrier, retaining the particles bigger than the pore size, as the smaller molecules go through the pores. Removing all micro-organisms and particles reliably, without any effects on the ingredients during the whole process.

Essential Technical Parameters

* Home-made Nylon Membrane Filters supply all the listed Pore sizes, while home-made PTFE Filters only provide sizes of 0.1, 0.22, 0.45, 0.8, 1.0, 3.0 μm.
* The bubble point is used for testing if the pore size is qualified.

Material of the filter membrane

Filter membrane materials include nylon, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), mixed cellulose (MCE), cellulose acetate (CA), glass fiber (GF), Polypropylene (PP), polyethersulfone (PES).

Its application includes HPLC sample preparation, routine QC analysis, protein deposit movement, dissolution test, food analysis, biofuel analysis, and environmental testing. We chose some of them for a detailed introduction. For all membrane features and performance, please contact Hawach directly(email: membrane@hawach.com or tel: +86-29-89284429).

Features

1. High porosity: High porosity allows air and liquid to provide high filtration rates in each zone. High porosity also provides a large surface area for adsorption and binding.
2. Diversity: There are many different types of filter membranes, and you can easily find the products you need in our various membranes.
3. High purity: All membranes are produced with high-purity raw materials and auxiliaries.
4. High strength: Our membranes have been tested for both rupture and tensile strength. PPTFE membranes and nylon membranes have strong chemical resistance.
5. Heat resistance: It has excellent heat resistance and low-temperature resistance.
6. Suitability: There is a low coefficient of friction.
7. Moisture resistance: the surface is not wet with water or oil, so it is not easy to dip the solution during operations.
8. Wear resistance: under high load, it has excellent wear resistance.
9. Corrosion resistance: it can protect parts from any kind of chemical corrosion.
10. Membrane filters are applicable for both non-sterile and sterile conditions
11. The applications rely on distinguishing the sizes of the membranes.