Major Categories of Filter Cartridges

Principles and Differences Between Internal-Pressure and External-Pressure Ultrafiltration Membranes

1. PP Filter Cartridge

Also known as PP melt-blown filter cartridge, it is made from polypropylene superfine fibers that are thermally fused and entangled. The fibers form a three-dimensional microporous structure with randomly distributed pores, where the pore size gradually decreases along the flow direction of the filtrate. This combines surface, depth, and precision filtration into one, capable of retaining impurities of different particle sizes. Filtration accuracy ranges from 0.5 to 100 μm, with a flux more than 1.5 times that of comparable pleated filter cartridges of the same precision. Various end-cap connections are available to suit different engineering installation needs.

2. String-Wound Filter Cartridge

Made by precisely winding textile fiber yarn with good filtration performance around a porous core. The yarn materials include polypropylene fiber, acrylic fiber, and degreased cotton fiber. By controlling the winding tightness and density, filter cartridges with different filtration accuracies can be produced. They effectively remove suspended solids and particulate impurities from liquids, providing a high purification effect for various liquid types.

3. Pleated Microporous Filter Cartridge

Made using filtration media such as polypropylene (PP) melt-blown fiber membrane, nylon (Nylonb), or polytetrafluoroethylene (PTFE) microporous membrane. These precision filter elements are small in size, have a large filtration area, and offer high accuracy. Filtration accuracy ranges from 0.1 μm to 60 μm. End-cap sealing and overall structure are bonded by thermal welding. Common connection types are: 222, 226, and flat-end. Each product undergoes strict integrity testing before leaving the factory to ensure stable performance.

4. Activated Carbon Filter Cartridge

Two main types: compressed activated carbon and loose-packed activated carbon.

1. Compressed activated carbon: Uses high-adsorption coal-based or coconut shell activated carbon as the filtration medium, combined with food-grade binders and formed under heat and pressure. The carbon core is wrapped inside and outside with a non-woven fabric filter layer to prevent carbon powder leakage. Both ends have soft nitrile rubber sealing gaskets for good sealing inside the filter housing.

2. Loose-packed activated carbon: Activated carbon granules are filled into a specially made plastic shell. The shell ends are welded with caps, and a non-woven filter sheet is placed at both ends to prevent carbon powder leakage. End caps can be made in different connection types (flat-press, pipeline type such as models 4042, 4044, 4046).

5. Dual-Section Filter Cartridge

• Upper section: Polypropylene melt-blown filter cartridge with 5 μm precision

• Lower section: Granular activated carbon cartridge containing 170 g activated carbon

• Material: ABS, PP

• Length: 250 mm, Outer diameter: 70 mm

• Flow rate: 8 L/s, Total throughput: 6–8 tons

• Activated carbon indicators: Strength > 90; Iodine value (mg/g) > 950; Methylene blue value (mg/g) > 120

6. Ceramic Filter Cartridge

Made from pure natural physical materials, so it does not cause secondary pollution during use. Unlike pure water machine filters that remove all minerals, ceramic filters retain beneficial minerals while effectively removing sediment, bacteria, and rust. They never clog, have a long service life, and perform excellently even with poor water quality. The world’s highest-precision ceramic filter is the dual-control membrane type, with an average pore size of 0.1 μm. Water filtered through it meets the national direct-drinking water standard without boiling.

7. Resin Filter Cartridge

Resin is a porous, insoluble ion-exchange material. The resin filter cartridge in a water softener contains millions of tiny plastic beads, each with many negatively charged ion-exchange sites. In its fresh state, these sites are occupied by sodium ions. When calcium and magnesium ions pass through, they replace sodium ions because they carry stronger positive charges. The replaced sodium ions leave with the water, producing “soft” water. Once all sites are occupied by calcium and magnesium, the resin can no longer function until regenerated.

8. Titanium Rod Filter Cartridge

Has excellent corrosion resistance, high-temperature resistance, high strength, stable filtration precision, and easy regeneration. Made from titanium powder through molding and high-temperature sintering, so surface particles do not easily shed. Can withstand 500–600 °C in air, suitable for filtering various corrosive media such as hydrochloric acid, sulfuric acid, alkalis, seawater, aqua regia, and chloride solutions of iron, copper, sodium, etc. Has excellent machinability, can be cut or welded, withstands internal pressure up to 2 MPa. Porosity is 35–45%, with uniform pore distribution, large dirt-holding capacity, and simple regeneration for repeated use.

9. RO Reverse Osmosis Filter Cartridge

Uses an RO membrane. Reverse osmosis (RO) technology—developed by NASA with international collaboration and heavy investment—applies pressure greater than the natural osmotic pressure to force water molecules from the high-concentration side to the low-concentration side. Since RO membrane pores are hundreds to thousands of times smaller than viruses and bacteria, contaminants such as viruses, bacteria, heavy metals, dissolved solids, organic pollutants, and calcium/magnesium ions cannot pass through, achieving water softening and purification.

10. Stainless Steel Filter Cartridge

Features:

1. Excellent filtration performance for particle sizes 2–200 μm with uniform surface filtration

2. Good corrosion, heat, pressure, and wear resistance

3. Uniform pores and precise filtration accuracy

4. Large flow per unit area

5. Suitable for both low and high temperatures; reusable after cleaning

Applications:
Petrochemical, oil pipeline filtration, fueling equipment, construction machinery fuel filtration, water treatment systems, pharmaceuticals, and food processing. Rated flow: 80–200 L/min, working pressure: 1.5–2.5 MPa, filtration area: 0.01–0.20 m², filtration precision: 2–200 μm. Filter material: stainless steel woven mesh or perforated mesh, suitable for pre- and post-treatment systems, further purifying water with suspended solids < 2–5 mg/L.

11. Oil Filter Cartridge

Available in various specifications and materials, with filtration accuracy from 0.5 to 80 μm, suitable for different industrial conditions and oil types.

12. Hydraulic Oil Filter Cartridge

Mainly used in hydraulic systems to filter oil, removing particulate matter and rubber impurities to maintain oil cleanliness, ensuring the normal operation of the hydraulic system.