Folding filter element are the core filtration consumables in industrial precision filtration, pure water production, biopharmaceuticals, and fine chemical processes. The mainstream materials include PP, PES, PVDF, and PTFE. Different filter elements have significant differences in thermal resistance, chemical compatibility, surface hydrophobicity, and precise filtration stability. Improper process selection can easily lead to filter element damage, medium leaching, rapid filter membrane clogging, etc., thereby causing fluid contamination, process downtime, and non-compliant product quality in production. Based on the core physical and chemical properties and process compatibility of various materials, this article sorts out a standardized selection scheme to provide precise and reliable technical references for pleated membrane filter element selection in different working conditions.
PP (Polypropylene) folded filter elements are the preferred choice for cost-effectiveness and are the most widely used basic Pp filter Element. They have good chemical stability, can withstand weak acids and weak alkalis, do not have additive leaching, have excellent deep filtration capacity, large pollutant capacity, are not prone to damage, and are inexpensive. However, their thermal resistance is relatively weak, with a maximum working temperature of only 60°C, and they are not resistant to organic solvents and strong corrosive media. They are suitable for mild working conditions such as ordinary industrial water treatment, tap water pretreatment, food and beverage coarse filtration, and primary oil purification, and are the optimal choice for low-budget and routine filtration scenarios of polypropylene pleated filter element.
PES folded filter elements focus on precision water treatment and biological filtration. The material is hydrophilic membrane material， with excellent water wettability， fast water flow， uniform filtration accuracy， and excellent thermal resistance， can be repeatedly sterilized at high temperatures， has low leaching and adsorption， and will not contaminate drug solutions and pure water media. It is not resistant to strong solvents and concentrated strong alkalis， and is highly targeted in application scenarios， mostly used in pharmaceutical injection solutions， biological culture solutions， ultra-pure water terminal filtration， food and beverage aseptic clarification， etc.， and is the mainstream pp pleated filter cartridge in the biopharmaceutical industry.
PVDF (Polyvinylidene Fluoride) folded filter elements have excellent stability and wide versatility， divided into two types： hydrophilic and hydrophobic. Compared with PP filter elements， its thermal resistance， corrosion resistance， and anti-pollution performance have been comprehensively upgraded， with excellent material toughness， not prone to cracking， and longer service life. The hydrophilic type is suitable for water-based media filtration such as pure water and fine pharmaceutical solutions， while the hydrophobic type can meet the filtration requirements of gases and low surface tension liquids. Compared with high-performance PTFE filter elements， PVDF filter elements have significant cost advantages and can be widely used in electronic process cleaning water， fine chemical solutions， mild corrosive fluids， etc.， and are the ideal choice for mid-range precision filtration scenarios replacing ordinary Folding filter element.
PTFE (Polytetrafluoroethylene) folded filter elements are high-end specialized filter elements suitable for extremely complex working conditions. Among the four types of filter elements， they have the top chemical tolerance performance， can withstand strong acids， strong alkalis， various organic solvents， and strong oxidants， and have excellent anti-corrosion performance， high material toughness， not prone to cracking， and longer service life. They are mainly used in highly corrosive chemical solutions， high-purity electronic chemicals， high-temperature corrosive fluids， and sterilization of compressed air， etc.， which are scenarios that ordinary pleated membrane filter element cannot adapt to. Their only drawback is that the procurement cost is relatively high， and even after hydrophilic modification， the water flow rate is slightly lower than that of PES filter elements， and they are not suitable for routine pure water filtration scenarios.
Based on the material properties and application characteristics of the above four mainstream folded filter elements， a standardized selection basis can be formed： for conventional mild working conditions and cost priority scenarios， polypropylene pleated filter element are preferred； for high-precision hydrophilic filtration scenarios such as biopharmaceuticals， ultra-pure water production， and aseptic pharmaceutical solutions， PES filter elements are suitable； for mid-range precision fluid filtration scenarios with mild corrosion characteristics， PVDF filter elements are recommended； for extreme harsh working conditions such as strong corrosive chemical solutions， high-purity electronic chemicals， high-temperature corrosive fluids， and sterilization of compressed air， PTFE filter elements with the best corrosion resistance should be selected. In actual selection and application, multiple factors such as medium properties, working temperature, filtration accuracy, industry compliance standards, and project budget need to be comprehensively considered. The most suitable pp pleated filter cartridge and Pp filter Element should be selected to maximize the filtration efficiency, enhance the stability of the system operation, reduce material consumption, and ensure the continuous compliance and efficient operation of the production process.