Nomex Filter Bags
High-Performance Meta-Aramid Baghouse Filter Bags for Continuous Operation up to 204 °C
Industry-standard filtration media for baghouse dust collectors in asphalt plants, cement kilns, steel mills & power generation. Engineered by ECOGRACE.
✓ 25+ Years Experience
✓ 80+ Countries
✓ 99.9% Efficiency
Nomex filter bags (meta-aramid needle felt) are manufactured from DuPont™ Nomex® meta-aramid fibers, delivering exceptional thermal stability, outstanding abrasion resistance, and reliable chemical durability — making them the preferred choice for asphalt mixing plants, cement kilns, steel mills, power generation facilities, and dozens of other high-temperature industrial processes.
ECOGRACE Nomex baghouse filter bags achieve particulate emission levels below 10 mg/Nm³ with service life of 24 – 36 months. Every bag undergoes rigorous quality testing — from fiber-level tensile strength verification to full-bag burst-pressure testing — before shipment.
What Is a Nomex Filter Bag?
A Nomex filter bag is a dust collection filter element manufactured from meta-aramid (polyamide-imide) needle-punched felt. Meta-aramid fibers possess a unique molecular structure — aromatic rings connected by amide linkages — granting inherent flame resistance, exceptional dimensional stability, and superior resistance to organic solvents. Unlike polyester (degrades above 130 °C) or acrylic (limited to 125 °C), Nomex maintains mechanical integrity at continuous temperatures up to 204 °C (400 °F).
204 °C (400 °F)
220 °C (428 °F)
28 – 30 %
3–5× vs Fiberglass
≥ 85% Retained
No Melt (370°C decomp)
Understanding Aramid Fiber: What Makes Nomex® the Industry Standard
Aramid fibers are synthetic aromatic polyamide fibers known for exceptional strength-to-weight ratio, heat resistance, and dimensional stability. Meta-aramid (Nomex® by DuPont, Conex® by Teijin) is the most widely used for baghouse filter bags.
Meta-Aramid (Nomex®)
Engineered for thermal & electrical insulation. Excellent heat resistance without melting, outstanding dimensional stability, good chemical resistance. The ideal fiber for hot gas filtration.
Para-Aramid (Kevlar®)
Extreme tensile strength but not suitable for filter bags due to UV degradation sensitivity and higher cost. Used in ballistic/structural applications.
Key Molecular Properties
Nomex vs. Other High-Temperature Filter Media
Comprehensive comparison across key performance parameters for informed media selection.
| Parameter | Nomex (Aramid) | PPS (Ryton) | PTFE (Teflon) | P84 | Fiberglass | Polyester |
|---|---|---|---|---|---|---|
| Max Continuous Temp | 204 °C | 190 °C | 260 °C | 240 °C | 260 °C | 130 °C |
| Abrasion Resistance | ★★★★★ | ★★★☆☆ | ★★★☆☆ | ★★☆☆☆ | ★☆☆☆☆ | ★★★★★ |
| Flex / Fold Resistance | ★★★★★ | ★★★☆☆ | ★★★☆☆ | ★★☆☆☆ | ★☆☆☆☆ | ★★★★★ |
| Acid Resistance | Good | Excellent | Excellent | Good | Fair | Good |
| Hydrolysis Resistance | Moderate | Excellent | Excellent | Poor | Good | Poor |
| Typical Service Life | 24–36 mo | 24–36 mo | 36–60 mo | 24–36 mo | 12–24 mo | 18–24 mo |
| Best Fit | Asphalt, Cement, Steel | Coal Boiler, WTE | Chemical, WTE | Cement, WTE | Power, Cement | General |
💡 Key takeaway: Nomex offers the best balance of abrasion resistance, flex durability, and cost-effectiveness in the 150–204 °C range. For mechanical stress applications, it outperforms fiberglass and P84 by 50–100% in service life.
Technical Specifications
ECOGRACE manufactures Nomex filter bags in a comprehensive range of specifications to match all major baghouse designs.
| Base Material | 100% Meta-Aramid (Nomex®) Needle Felt |
| Weight | 500 g/m² (standard) | 550 g/m² | 600 g/m² (heavy duty) |
| Thickness | 1.6 – 2.2 mm |
| Air Permeability | 12 – 18 m³/m²/min @ 200 Pa |
| Tensile Strength (Warp/Weft) | ≥ 800 / 1000 N/5cm |
| Operating Temp (Continuous / Peak) | 204 °C / 220 °C |
| Surface Treatment | Singe + Calender (std) | PTFE Membrane | W&O Repellent | Anti-static |
| Bag Diameters | Ø 120, 130, 150, 160, 200, 250 mm (custom available) |
| Bag Lengths | 1,000 – 10,000 mm (custom cut-to-length) |
| Top / Bottom Config | Snap band | Spring ring | Sewn-in ring | Raw edge | Clamp ring |
| Filtration Efficiency | ≥ 99.9% (standard) | ≥ 99.99% (PTFE membrane) |
| Outlet Emission | ≤ 20 mg/Nm³ (standard) | ≤ 5 mg/Nm³ (PTFE membrane) |
Surface Treatment Options
Multiple finishing technologies can be applied individually or in combination to optimize performance.
Singeing + Calendering
STANDARD
Heat-singed and roller-compressed for smooth filtration surface. Improves cake release, reduces ΔP by 15–20%.
PTFE Membrane Lamination
PREMIUM
Microporous PTFE membrane (0.2–2.0 μm) for surface filtration. Emission ≤5 mg/Nm³, 30–50% longer bag life.
Water & Oil Repellent (W+O)
MOISTURE PROTECT
Fluorocarbon coating for hydrophobic/oleophobic properties. Essential for asphalt plants with bitumen oil mist.
Anti-Static Treatment
ATEX/NFPA
Conductive fibers (SS/carbon) blended at 2–5%. Surface resistivity ≤10⁹ Ω for combustible dust environments.
Acid-Resistant Coating
CHEMICAL
For moderate acid gas (SO₂ <800 ppm). Extends chemical resistance without upgrading to PPS or PTFE.
Easy-Clean (Glazed) Finish
STICKY DUST
Ultra-smooth glass-like surface for maximum cake release. Reduces pulse cleaning frequency by 20–30%.
Applications by Industry
Nomex filter bags serve a wide range of high-temperature industrial dust collection applications.
Asphalt Mixing Plants
160–200 °C | Oil mist + abrasive mineral dust
Single largest application worldwide. W&O treated Nomex bags provide 24–36 month service life across batch, drum, and mobile plants.
Cement Production
130–200 °C | Alkaline dust + SO₂/CO spikes
Raw mill, finish mill, clinker cooler, coal mill baghouses. For kiln tail >200 °C, upgrade to PPS or PTFE.
Steel Mills & Foundries
140–200 °C | Spark hazards + metallic dust
EAF, BOF, ladle furnaces. Anti-static Nomex withstands aggressive pulse-jet cleaning (every 3–5 sec).
Power Generation & Biomass
150–200 °C | SO₂/NOx + moisture + variable load
PTFE membrane Nomex for ultra-low emissions (≤10 mg/Nm³) with wide turndown ratio capability.
Carbon Black Production
160–200 °C | Sub-micron dust + combustible
PTFE membrane + anti-static mandatory. Captures 20–300 nm particles while maintaining cleanability.
Waste Incineration / WTE
160–200 °C | Acid gases + heavy metals
Cost-effective alternative in smaller WTE baghouses with upstream dry sorbent injection (DSI).
Chemical & Pharmaceutical
120–180 °C | Product recovery + chemical exposure
Spray dryers, fluid beds. FDA-grade available for pharmaceutical validated cleaning applications.
Food & Grain Processing
100–180 °C | Explosive dust + hygiene
Anti-static Nomex with LOI 28–30 + conductive fiber blending for explosion protection in food-grade installations.
Nomex Filter Bag Selection Guide by Application
Choose the right Nomex configuration based on your operating conditions and dust characteristics.
| Application | Weight (g/m²) | Surface Treatment | Operating Temp | Key Feature |
|---|---|---|---|---|
| Asphalt Batch Plant (Dryer) | 550 | Singe + W&O | 160–200 °C | Oil mist rejection |
| Cement Raw Mill | 500 | Singe + Calender | 130–180 °C | Cake release |
| Coal-Fired Power ESP Replacement | 550 | PTFE Membrane | 150–190 °C | Ultra-low emission |
| EAF Steel Mill | 600 | Singe + Anti-static | 140–200 °C | Spark resistance |
| Carbon Black Reactor | 550 | PTFE + Anti-static | 160–200 °C | Sub-micron capture |
| Biomass Boiler | 500 | W&O + Calender | 150–190 °C | Moisture tolerance |
| Grain/Feed Dryer | 500 | Anti-static + Singe | 100–160 °C | ATEX compliance |
PTFE Membrane Upgrade: Standard vs. Premium Nomex Bags
Adding a microporous PTFE membrane transforms Nomex from depth-filtration to surface-filtration media — dramatically improving efficiency while extending bag life. Learn more about PTFE filter bag technology.
| Parameter | Standard Nomex | PTFE Membrane Nomex |
|---|---|---|
| Filtration Mode | Depth filtration | Surface filtration |
| Outlet Emission | ≤ 20 mg/Nm³ | ≤ 5 mg/Nm³ |
| Operating ΔP | 800 – 1500 Pa | 500 – 1000 Pa |
| Cake Release | Good | Excellent (near-zero residue) |
| Expected Service Life | 24 – 36 months | 36 – 48 months |
| Best For | General applications | Ultra-low emission / sticky dust |
Common Nomex Filter Bag Failure Modes & Prevention
Understanding failure mechanisms helps you select the right bag specification and extend service life.
Thermal Degradation
HIGH RISK
Sustained temp >220 °C causes fiber embrittlement. Prevention: Install high-temp cutoff; consider P84 blends for excursion-prone systems.
Hydrolysis Attack
MODERATE RISK
Moisture + heat (>150 °C) degrades amide bonds over time. Prevention: Keep dew point margin ≥25 °C; use W&O treatment.
Abrasion Wear
HIGH RISK
High A/C ratio or poor gas distribution. Prevention: Use 550–600 g/m² heavy-duty; install inlet diffusers; maintain A/C <1.2 m/min.
Chemical Attack (Acid)
MODERATE RISK
Strong mineral acids (H₂SO₄, HCl >50 ppm) degrade Nomex. Prevention: Upgrade to PPS or PTFE for acid-rich conditions.
Moisture Blinding
OPERATIONAL
Condensation blocks pores, ΔP spikes. Prevention: Insulate housing; pre-heat; use PTFE membrane for hydrophobic barrier.
Pulse Cleaning Fatigue
OPERATIONAL
Excessive cleaning pressure or frequency. Prevention: Optimize pulse pressure (4–6 bar); implement on-demand cleaning by ΔP trigger.
Case Studies: Nomex Filter Bags in Action
Real-world performance data from recent ECOGRACE installations across Asia-Pacific.
Why Choose ECOGRACE Nomex Filter Bags?
25+ years manufacturing experience, 80+ countries served, ISO-certified quality management — your reliable partner for high-temperature filter bags.
Manufacturing Process: From Fiber to Finished Bag
Every ECOGRACE Nomex filter bag passes through 6 critical production stages with in-line quality verification.
Fiber Opening & Blending
Nomex staple fibers (2–5 denier) opened, carded, and cross-lapped into uniform web. Optional: blend with PTFE/anti-static fibers.
Needle Punching
High-density needle-punching (800–1500 punches/cm²) interlocks fibers onto woven aramid scrim for tensile strength.
Heat Setting & Surface Treatment
Thermal stabilization at 210–230 °C to lock dimensions (<1% shrinkage). Then singeing, calendering, or PTFE membrane lamination.
Cutting & Sewing
CNC auto-cutting for precision dimensions (±2 mm). Double-needle sewing with Nomex thread for seam integrity.
Ring & Fitting Assembly
Snap bands, spring rings, or sewn-in rings attached per OEM specifications. Ultrasonic welding available for sealed bottoms.
QC Testing & Packaging
100% visual inspection + random sampling for weight, thickness, tensile, air perm, and burst pressure. Vacuum-packed for shipment.
Frequently Asked Questions — Nomex Filter Bags
What is the maximum temperature for Nomex filter bags?
Nomex filter bags operate continuously at up to 204 °C (400 °F) and can withstand short-term temperature excursions up to 220 °C. For sustained temperatures above 204 °C, consider upgrading to P84 or PTFE filter bags.
How long do Nomex bags last in asphalt plants?
With proper W&O treatment and correct A/C ratio (<1.0 m/min), ECOGRACE Nomex bags typically achieve 24–36 months service life in asphalt mixing plants. Factors affecting life include operating temperature consistency, pulse cleaning optimization, and moisture management.
What is the difference between Nomex and aramid filter bags?
Nomex® is DuPont’s brand name for meta-aramid fiber. “Nomex filter bag” and “aramid filter bag” refer to the same product. Other meta-aramid brands include Conex® (Teijin) and domestic equivalents — all are functionally identical in filtration performance.
When should I choose Nomex over PPS filter bags?
Choose Nomex when: (1) abrasion resistance is critical (mineral dust, high-velocity cleaning); (2) flex resistance matters (aggressive pulse-jet); (3) acid gas is low (<50 ppm SO₂). Choose PPS when: high acid/alkali environment or when both acid and temperature are concerns simultaneously.
Can Nomex bags handle moisture and condensation?
Standard Nomex has moderate moisture resistance. For high-humidity applications (asphalt, biomass), we recommend W&O (Water & Oil repellent) treatment or PTFE membrane lamination to prevent moisture blinding and extend bag life.
What standard sizes do you offer?
Standard diameters: Ø120, 130, 150, 160, 200, 250 mm. Standard lengths: 1,000–10,000 mm. We also manufacture 100% custom dimensions matching OEM specifications from all major dust collector manufacturers worldwide.
What is the MOQ and lead time?
MOQ: 100 pieces for standard sizes (negotiable for first orders). Lead time: 7–15 working days for standard configurations, 15–25 days for custom specifications. Free samples available for testing.
Do you provide PTFE membrane Nomex bags?
Yes. ECOGRACE offers PTFE membrane laminated Nomex bags achieving ≤5 mg/Nm³ emission. The ePTFE membrane (0.2–2.0 μm pore size) provides true surface filtration — lower ΔP, better cake release, and 30–50% longer service life compared to standard felt. Learn more about PTFE filter bag technology.
How do I determine the right bag weight (gsm)?
500 g/m²: General applications, low-to-moderate dust load. 550 g/m²: Standard for most industrial use (asphalt, cement, power). 600 g/m²: Heavy-duty for extreme abrasion or high-velocity cleaning. Contact us with your operating conditions for a tailored recommendation.
Can you match bags from other manufacturers?
Absolutely. Provide your current bag dimensions, ring type, and operating conditions — or send a sample bag — and we’ll produce drop-in replacements. We routinely match specifications for all major baghouse OEMs including Donaldson, BWF, Testori, and others.
Related High-Temperature Filter Bags
Explore our complete range of high-temperature baghouse filter media for different operating conditions.
Get Your Nomex Filter Bag Quote Today
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Free samples available • MOQ 100 pcs • Lead time 7–15 days