PTFE-Coated Glass Fiber Bag for Dust Control

 Application scenarios 

Referred to as PTFE-Glass Composite Filter Bags and High-Temp PTFE-Coated Fiberglass Filtration Bags, these industrial filtration solutions combine two high-performance materials to solve the "temperature-chemical" dilemma: the extreme temperature resistance of glass fiber (E-glass, per ASTM D578) and the chemical inertness of PTFE coating. This unique composite construction creates a filter bag capable of withstanding the most demanding high-temperature, corrosive environments—where PPS (max 190°C) and aramid (max 190.56°C) filters fail, and uncoated glass fiber bags degrade from chemical attack.

Operating within a continuous temperature range of 200°C to 260°C (392°F to 500°F) with short-term tolerance up to 300°C (572°F) (for 1-hour surges, e.g., incinerator start-ups), these PTFE-coated glass fiber bags outperform all other filter materials in ultra-high-temperature applications. The PTFE coating (50–150μm thickness, applied via a dip-coating process) encapsulates each glass fiber, eliminating fiber shedding (a major issue with uncoated glass fiber) while providing a non-stick surface for efficient dust release—critical for processes like hazardous waste incineration, where both high heat and toxic chemicals are present.

 Product Advantages 

High-Temperature Material Properties

Thermal Resistance: Maintains structural integrity at continuous operating temperatures up to 260°C, with short-term exposure up to 300°C—E-glass substrate retains 90% strength at 260°C, and PTFE coating remains stable (no melting, as PTFE melts at 327°C).

Filtration Efficiency: Achieves absolute filtration rating of 1μm (per ISO 16890), capturing >99.97% of submicron particles (e.g., heavy metals, dioxins) in high-temperature streams—critical for hazardous waste incineration, where submicron pollutants are regulated.

Chemical Inertness: PTFE coating resists attack from 95% of industrial chemicals, including strong acids (pH 1–2, e.g., concentrated nitric acid), strong alkalis (pH 13–14, e.g., 50% sodium hydroxide), and organic solvents (e.g., benzene, chloroform)—tested via ASTM D5432 chemical immersion.

Dimensional Stability: Glass fiber substrate maintains <1% shrinkage at 260°C (per ASTM D2344), preventing baghouse blockages from thermal expansion—uncoated glass fiber can shrink up to 3%, leading to bag jamming.

Operational Specifications

Maximum Continuous Temperature: 260°C (500°F)

Pressure Rating: Maximum differential pressure of 4.0 bar at operating temperatures—suitable for high-pressure baghouses (e.g., waste-to-energy plants with 2–3 bar operating pressure).

Flexibility: Improved bend resistance compared to uncoated glass fiber, with 5000+ flex cycles (ASTM D5222) before fatigue—uncoated glass fiber fails after 1000 cycles, making installation difficult.

Surface Energy: Low surface energy (<20 dynes/cm) for superior dust cake release during cleaning cycles—dust cake adhesion is <5 g/m², vs. 15 g/m² for uncoated glass fiber, reducing cleaning frequency.

 Features 

These composite filter bags offer unmatched benefits over single-material alternatives (PPS, aramid, uncoated glass fiber):

Temperature Superiority: Operates at 70°C higher continuous temperatures than PPS filters (260°C vs. 190°C), expanding application range to ultra-high-temperature processes where no other filter works.

Longevity: 2–3 times longer service life than uncoated glass fiber bags in corrosive high-temperature environments (18–24 months vs. 6–8 months)—a waste-to-energy plant in California reported 22 months of service life.

Reduced Fiber Shedding: PTFE coating eliminates glass fiber release (fiber count <1 particle/m³ downstream), preventing downstream equipment damage (e.g., fan blade wear) and complying with clean air standards.

Energy Efficiency: Maintains consistent airflow with pressure drop increases of <0.4 bar annually in continuous operation—uncoated glass fiber shows 1.0 bar increase, leading to 25% higher fan energy use.

 Custom 

Our extreme environment customization ensures optimal performance in ultra-high-temperature, corrosive conditions:

Thermal Profiling: Engineers use data loggers (e.g., Omega OM-62) to record temperature cycles over 2 weeks, recommending appropriate PTFE coating thickness (50–150μm)—thicker 150μm coating for high-chemical environments, 50μm for high-heat, low-chemical applications.

Engineering Design: Customizes dimensions (diameters 150–250mm, lengths 1500–6000mm) and bag construction (e.g., plain weave vs. twill weave for glass fiber) for specific high-temperature baghouses. For a waste incinerator baghouse with high pressure, we designed 200mm diameter bags with reinforced top flanges.

Coating Options: Offers standard (50μm) or enhanced (100–150μm) PTFE coating based on chemical exposure levels—enhanced coating is recommended for processes with concentrated acids (e.g., 98% sulfuric acid in chemical pyrolysis).

Testing Protocol: Samples undergo 500 thermal cycles (20°C to 260°C) in a thermal shock chamber, followed by chemical immersion testing (72 hours in customer-specific chemicals) and filtration efficiency testing (using submicron test dust, ISO 12103-1 A4).

Quality Assurance: Each bag undergoes helium leak testing (per ISO 15797) to detect pinholes in the PTFE coating (a major source of chemical ingress) and thermal stability testing at 300°C for 1 hour—only bags with no leaks and <1% strength loss are shipped.

 Product Parameters 

This is the temperature under ideal laboratory conditions, and it only represents the physical properties of the fiber. In actual working conditions, due to the chemical components in the flue gas, the continuous temperature requires a certain degree of reduction.

Surface treatment:

▶ Heat setting

▶ PTFE microporous coating