What Types of Cores are Used in String Wound Filter Cartridges?
Polypropylene (PP): The most common base material with outstanding acid/alkali resistance and chemical stability. It operates from -10°C to 60°C and is widely used for pre-filtration in drinking water treatment, food, and beverage industries.
Stainless Steel: It utilizes medical-grade stainless steel woven mesh, capable of withstanding 400°C temperatures and supporting reverse flushing and reuse. It excels in high-purity water systems for pharmaceutical and electronics industries, with an initial filtration accuracy of 5 microns.
Glass Fiber: It consists of ultra-fine glass wool wound through a unique process, offering exceptional high-temperature resistance. When combined with a silicone resin coating, it withstands strong acid and alkali environments, making it irreplaceable in specialized applications like electroplating liquid filtration.
Cotton: It uses medical-grade long-staple cotton, degreased for purity. The 3D fiber bed formed by natural fibers exhibits a unique affinity for oily substances. It excels in filtering lubricating oil, hydraulic oil, and similar fluids, though its heat resistance is limited to below 80°C.
Advantages Of String Wound Water Filter：
Excellent impurity retention capacity
Utilizing a gradient density winding process, the outer layer forms a loose ~50μm structure that initially traps large particles, while the inner dense 10μm layer efficiently captures fine impurities. Tests demonstrate a 98.7% single-pass efficiency for particles >5μm. The depth filtration mechanism grants 3-5× higher dirt capacity than same-size surface filters, markedly enhancing performance and lifespan.
Enhanced durable structure
The string wound water filter cartridges feature an internal 304 or 316L stainless steel skeleton, capable of withstanding bursting pressures up to 1.6MPa. The specialized hot-melt welding process ensures the fiber layer maintains structural stability under high-pressure impact, with axial compressive strength exceeding 200kg, enabling stable operation even during frequent start-stop conditions.
What are the Common Uses of the String Water Filters?
Municipal/industrial water treatment: removing pipe particles (silt, rust), protecting UF/RO membranes, and extending system life; also used in boiler feedwater and cooling water pretreatment.
Beverage/food filtration: clarifying syrups, juices, oils, and wines to enhance clarity, stability, and quality.
Chemical liquid filtration: filtering corrosive fluids (e.g., plating solutions, acids/alkalis) – fiberglass or reinforced PP materials are preferred.
Solvent recovery/treatment: paired with activated carbon/PP to purify esters, ketones, etc., removing organics for higher purity.
Pharmaceutical purification: meeting strict particulate standards for intermediates, process water, and liquid drug pre-filtration.
How To Select A String Wound Cartridge Filter?
For accuracy selection: 50–100μm suits removing large particles like rust and sand; 5–20μm works for fine filtration to protect precision equipment; while 1–5μm meets high-standard processes such as electronic-grade pure water and biopharmaceuticals. The filter cartridge’s material and structure directly impact performance, and proper selection can significantly enhance system filtration efficiency and operational effectiveness.
The operating conditions also influence filter cartridge selection. Standard PP cartridges suit -10°C to 60°C, while reinforced PP extends to -20°C to 80°C. Stainless steel cartridges withstand extreme temperatures (-196°C to 400°C), ideal for high-temperature or special liquid filtration.
For high turbidity liquids (>100NTU), opt for wide-flow-channel designs to reduce pressure drop and prolong service life. Additionally, verify the cartridge’s length and interface compatibility with system pressure levels to ensure proper installation and stable operation.
