What Are PES Filters?  

PES (polyethersulfone) filters are high-precision filtration solutions renowned for their exceptional performance in sterile and aqueous applications. Composed of a naturally hydrophilic asymmetric PES membrane, these filters combine ultra-low protein binding with robust chemical compatibility, making them ideal for critical processes in pharmaceuticals, electronics, and food industries. Membrane Solutions’ PES pleated cartridge filters, such as the SteriPure series, are engineered with a structure that includes PES filter membranes, polypropylene supports, and thermal-bonded components—ensuring zero adhesive contamination and high cleanliness.  

How Do PES Filters Work?  

The magic lies in the asymmetric PES membrane’s microstructure:  

- Pore Size Precision: Membranes with pore sizes ranging from 0.02μm to 1.0μm (e.g., 0.2μm for bacterial removal) trap particles while allowing liquid flow.  

- Hydrophilic Nature: The natural hydrophilicity of PES eliminates the need for wetting agents, reducing extractables and ensuring high flow rates.  

- Double-Layer Design (SteriPure-D): Some models feature dual-layer membranes for enhanced sterilization protection, meeting strict terminal filtration requirements.  

For example, the SteriPure-B series uses an optimized pleat structure to maximize filtration area (≥0.65m²/10inch), balancing high flux with long service life.  

Key Advantages of PES Filters  

1. Superior Sterilization Efficiency  

   - Bacterial endotoxin levels ≤0.25EU/mL and 100% integrity testing (bubble point and diffusion tests) ensure reliable sterility.  

   - Autoclavable up to 134°C for 20 minutes (30 cycles) and steam-in-place sterilization capability make them suitable for repeated use in hygienic processes.  

2. Chemical & Thermal Stability  

   - Compatibility across pH 1–14 and resistance to solvents like IPA (as seen in bubble point tests) make them versatile for harsh chemistries.  

   - Maximum operating temperature of 80°C and forward pressure up to 5.2bar@25°C ensure durability in demanding environments.  

3. Economic Efficiency  

   - The SteriPure-P series’ built-in pre-filter membrane reduces plugging, extending service life and minimizing replacement costs.  

   - High dirt-holding capacity (e.g., SteriPure-H for high-viscosity fluids) boosts process efficiency.  

Critical Applications of PES Filters  

- Pharmaceutical Industry: Sterilization of water for injection, APIs, vaccines, and eye drops. The low protein binding of PES ensures minimal product loss in biologic formulations.  

- Electronics: Ultra-pure water filtration for semiconductor manufacturing, where particle-free fluids are non-negotiable.  

- Food & Beverage: Sterilization of bottled water, wine, juice, and draft beer, preserving product clarity and shelf life without altering taste.  

Choosing the Right PES Filter  

Consider these factors to select the optimal cartridge:  

1. Pore Size: 0.2μm for bacterial removal; 0.45μm for general particulates.  

2. Membrane Structure: Single-layer (SteriPure-B) vs. double-layer (SteriPure-D) based on sterilization rigor.  

3. Flow Requirements: High-flux models like SteriPure-H for viscous liquids; long-life designs (SteriPure-P) for continuous processes.  

4. Regulatory Compliance: FDA 21 CFR 177, ISO 10993, and USP Class VI certification for pharmaceutical applications.  

Membrane Solutions: Setting the Standard in PES Filtration  

At Membrane Solutions, our PES filters undergo rigorous testing—from raw material sourcing to cleanroom manufacturing—to ensure consistency and purity. With customizable options (e.g., adaptor types, core materials) and global support, we deliver filtration solutions that balance performance, compliance, and cost-effectiveness.