Introduction To Different Filter Bag Materials

Introduction to Various Materials Used in Filter Bags: Filter bags are primarily manufactured using materials such as polypropylene (PP), polyethylene (PE), nylon, polytetrafluoroethylene (PTFE), and stainless steel (grades 304 and 316).

1. PP filter bags are made from meltblown or needle-punched polypropylene fibers. They resist acids and alkalis well, covering a pH range of 1 to 14. 

Operating temperature: ≤90°C (short-term resistance up to 100°C). 

Filtration accuracy range: 1μm to 200μm. Common specifications: 5μm, 10μm, and 25μm. 

Key advantages: 

Cost-effective, single-use design reduces cross-contamination risk, good hydrophilicity, suitable for aqueous solutions, and no extractable substances. 

These filter bags meet food-grade certifications (e.g., FDA). They are used in various applications, such as chemical pre-filtration (coatings and resins), clarification in food and beverage (fruit juice and beer), and pre-treatment in water processes (river and circulating water).

2.Material Characteristics of PE Filter Bags 

Composition: Made from ultra-high molecular weight polyethylene fiber. 

Chemical Resistance: Resistant to strong acids and alkalis (pH 0-14). 

Working Temperature: Up to 80℃. 

Filtration Accuracy: Ranges from 5μm to 300μm. The multi-layer gradient structure boosts dirt-holding capacity and prevents clogging. It also offers a long service life and a smooth surface. 

Backwashing: Easy to backwash and regenerate without fiber shedding, outperforming PP. 

Typical Applications： 

Electroplating: Filtration of copper hydroxide particles. 

Battery Electrolyte: Purification processes. 

High-Viscosity Fluids: Suitable for adhesives and oils.

3.PTFE Filter Bag Material Characteristics: 

Made from pure PTFE membrane and coated base fabric. 

Resistant to all organic solvents and strong corrosive chemicals. 

Working temperature range: -196℃ to 260℃. 

Ultra-high precision filtration accuracy: controls from 0.1μm to 10μm (β value >1000). 

Outstanding chemical inertness and aqua regia resistance. 

Features an anti-adhesion surface that is easy to clean. 

Strong hydrophobic properties. 

Typical Applications of Gas Filtration: 

Semiconductor ultra-pure water terminal filtration. 

High-temperature flue gas dust removal (boiler exhaust). 

Sterile filtration in the pharmaceutical industry (vaccines and injections).

4.Material Characteristics of Nylon Mesh Filter Bags: 

Composition: Made from nylon monofilament or multi-filament woven mesh. 

Chemical Resistance: Resistant to weak acids and weak bases (pH 4-11). 

Working Temperature: Up to 120℃. 

Filtration Accuracy: Ranges from 10μm to 500μm (controlled mesh size). 

Advantages: 

High mechanical strength 

Tear resistance 

Can be washed over 50 times 

Good flexibility 

Typical Applications: 

Machine tool coolant filtration (chip interception) 

Paint recovery in spray booths 

Agricultural irrigation systems (sand control filtration)

5.Material Characteristics of Stainless Steel Mesh Filter Bags: 

Made from 304/316L stainless steel wire. 

High temperature resistance (up to 500℃). 

Strong pressure and wear resistance.

Filtration accuracy: 5μm - 3000μm (50 mesh - 400 mesh). 

Advantages: 

Permanent service life. 

Zero consumable costs. 

Supports high-temperature steam sterilization. 

Stable structure that won’t collapse. 

Typical Applications: 

High-temperature melt filtration (polymer extrusion). 

Online filtration in pharmaceutical CIP systems. 

Coarse filtration of mining slurry (cyclone matching).