Aramid (Nomex®) Needle Punched Felt Filter Bag
Aramid (Nomex®) needle punched felt filter bags from LYH fit asphalt mixing plants, cement kilns, steel sintering, foundries, and high-temperature dry hot gas applications. Buyers choose Aramid filter bags when they need sustained service up to 204 °C in dry conditions, exceptional mechanical strength, and reliable abrasion resistance against high-velocity hot dust streams where polyester and acrylic cannot survive.
We supply Aramid / Nomex® meta-aramid filter bags from China with custom size discussion, fabric weight options (500–600 GSM), and full surface treatment support. If your project requires a specific bag diameter, length, top/bottom construction, or surface treatment match for your asphalt drum dryer, cement kiln tail, or foundry baghouse, we can review the RFQ and pair the right Aramid felt to your dust collector.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Material | 100% Meta-Aramid (Nomex® / equivalent) staple fiber, scrim-supported needle felt |
| Continuous Operating Temperature (Dry) | 204 °C / 400 °F |
| Continuous Operating Temperature (Moist) | 177 °C / 350 °F |
| Maximum Short-Term Surge Temperature | 240 °C / 464 °F |
| Specific Density | 1.38 g/cm³ |
| Moisture Regain (20 °C, 65% RH) | 4.5% |
| Standard Fabric Weight | 500 / 550 / 600 GSM (customizable) |
| Air Permeability | 12–18 m³/m²/min @ 200 Pa |
| Tensile Strength (Warp / Weft) | ≥ 1,200 N / 5×20 cm |
| Filtration Efficiency | ≥ 99.9% (with PTFE membrane: ≥ 99.99%) |
| Combustibility | Self-extinguishing (LOI ≥ 28) |
Material Properties
Outstanding High-Temperature Performance in Dry Hot Gas — Meta-aramid fiber maintains full mechanical integrity at 204 °C continuous service in dry conditions, with short-term peaks to 240 °C. This makes Aramid the standard choice for asphalt drum dryers, cement kilns, and other dry high-temperature exhaust streams.
Exceptional Mechanical Strength & Abrasion Resistance — Aramid has tensile strength roughly 2× polyester and superior abrasion resistance, allowing it to withstand high-velocity hot dust impingement, frequent pulse cleaning, and demanding mechanical conditions over years of service.
Excellent Dimensional Stability — Heat-set during manufacturing; Aramid felt resists thermal shrinkage and creep at elevated temperatures, ensuring consistent fit on the cage and stable filtration area throughout a typical 2–4 year service life.
Self-Extinguishing & Inherently Flame-Resistant — LOI ≥ 28; Aramid fiber does not support combustion and offers an additional layer of safety against ignition from sparks and embers, making it ideal for asphalt, foundry, and ferrous metal applications where ignition risk is elevated.
Good Resistance to Most Solvents & Mild Chemicals — Aramid resists most organic solvents and weak acids/alkalis at moderate temperatures, performing well in typical mineral and industrial dust streams.
Limitations to Note — Aramid is vulnerable to hydrolysis under combined high temperature and humidity (limit 177 °C in moist gas) and has poor resistance to strong acids and oxidizing agents. For acid dew point conditions, sulfur-rich flue gas, or saturated steam, choose PPS or PTFE instead. Aramid is also subject to UV degradation under direct sunlight exposure during storage.
Available Surface Treatments
| Treatment | Function | Recommended For |
|---|---|---|
| Singeing | Removes loose surface fibers via flame; improves cake release | Standard high-temp dry dust |
| Calendering / Glazing | Heated rollers densify the surface; enhances surface filtration | Fine-particle capture, low pressure drop |
| Heat Setting | Stabilizes felt dimensions, eliminates shrinkage during operation | All applications |
| PTFE Membrane Lamination | Microporous ePTFE membrane on dust side; emissions ≤ 5 mg/Nm³ | Ultra-low emission compliance, fine PM capture |
| Anti-Static | Conductive carbon fiber or stainless-steel filament; surface resistance 10³–10⁸ Ω·cm | Combustible dust in foundries, woodworking, metal grinding |
| Water & Oil Repellent (WO) | Enhanced moisture and oil rejection finish | Asphalt drum dryers, oily / sticky dust |
Bag Construction
- Top Constructions — Snap band, flange top, ring top, soft cuff, raw edge, strap top
- Bottom Constructions — Disc bottom, flat bottom, reinforced double-bottom, wear-strip bottom
- Sewing — 3-needle chain stitch with PTFE or aramid thread (high-temperature compatible); overlock or lockstitch on bottoms
- Reinforcement — Optional wear strips, custom skirts, double-bottom reinforcement for abrasive cement and sintering dust
Standard Sizes & Customization
| Dimension | Range |
|---|---|
| Diameter | Φ100 / 120 / 125 / 130 / 150 / 160 / 180 / 250 mm (or custom) |
| Length | 1,000 – 8,000 mm (custom lengths available) |
| Tolerance | Diameter ± 2 mm, Length ± 5 mm |
Non-standard sizes, special top/bottom configurations, and OEM patterns produced from your drawings or sample bag.
Industry Applications
- Asphalt Mixing Plants — drum dryer baghouse dedusting, the largest global application of Aramid filter bags
- Cement Plants — cement kiln tail, raw mill, clinker cooler with dry hot gas
- Steel Sintering — sinter plant exhaust dedusting at high temperature
- Foundries — shake-out, sand reclamation, melting furnace exhaust
- Iron & Steel — electric arc furnace (EAF), ladle refining, secondary dedusting
- Carbon Black & Petrochemical — process gas dedusting at moderate-to-high temperature
- Lime & Gypsum Plants — kiln exhaust dedusting (dry conditions)
- Non-Ferrous Smelting — copper, lead, zinc smelting exhaust
- Chemical Drying — spray dryer, fluid bed dryer with hot exhaust
- Glass & Ceramics — furnace exhaust dedusting at moderate temperatures
Why Choose LYH Aramid (Nomex®) Filter Bags
- Premium meta-aramid fiber — sourced from leading global producers (DuPont Nomex® or equivalent); scrim-supported felt for stability and abrasion resistance
- Strict QC on fabric weight, air permeability, tensile strength, thermal stability
- Full customization — any size, any top/bottom, any treatment combination
- Engineered for asphalt and cement duty — proven configurations for drum dryers, kiln tails, and sintering applications
- High-temperature sewing — all seams use PTFE or aramid thread for thermal compatibility
- Fast lead time — standard sizes ship in 10–20 days
- Engineering support — application engineers help match media to your gas temperature, humidity, and dust characteristics
- Reliable logistics — individually wrapped, ring-up packing, sea / air / courier shipment worldwide
FAQ
Q1: What is the maximum operating temperature of Aramid filter bags? Aramid (Nomex®) filter bags operate continuously at up to 204 °C (400 °F) in dry conditions and 177 °C (350 °F) in moist conditions, with short-term peaks up to 240 °C. For sustained operation above 204 °C, consider P84, fiberglass, or FMS composite alternatives.
Q2: Why choose Aramid over polyester or acrylic? Aramid offers significantly higher temperature tolerance (204 °C vs 135 °C polyester / 125 °C acrylic), much greater mechanical strength, and self-extinguishing flame resistance. Aramid is the preferred choice for asphalt drum dryers, cement kilns, and other dry hot gas applications above 135 °C where polyester and acrylic would degrade.
Q3: What is the difference between Aramid and Nomex®? “Aramid” is the generic fiber category (aromatic polyamide); “Nomex®” is DuPont’s registered trademark for meta-aramid fiber. They refer to the same fiber chemistry. LYH supplies Aramid filter bags using either DuPont Nomex® or equivalent meta-aramid fibers from leading producers, depending on customer specification.
Q4: How does Aramid compare to PPS? Aramid offers higher dry-temperature tolerance (204 °C vs PPS 190 °C) and superior mechanical strength, but is more vulnerable to hydrolysis and acid attack. PPS is preferred for sulfur-rich, moist, or acid dew point flue gas (coal-fired, waste incineration). Aramid is preferred for dry hot gas streams (asphalt, cement, foundry) where the gas is not chemically aggressive.
Q5: Is Aramid suitable for acid flue gas? No. Aramid has poor resistance to strong acids and oxidizing agents — particularly SOx and NOx at elevated temperature. For sulfur-laden coal flue gas or waste incineration exhaust, choose PPS, P84, or PTFE instead.
Q6: Can Aramid filter bags be PTFE-coated or anti-static? Yes. PTFE membrane lamination is available for ultra-low emission requirements. Anti-static treatment with carbon fiber or stainless-steel filament is available for combustible-dust applications such as foundries, metal grinding, and woodworking.
Q7: What is the typical service life of Aramid filter bags? In typical asphalt and cement applications, Aramid filter bags deliver 2–4 years of service life. Service life depends heavily on operating temperature, humidity, dust abrasiveness, and pulse-cleaning frequency.
Q8: What information do I need to provide for a quote? (1) bag dimensions, (2) top/bottom construction, (3) operating temperature & humidity, (4) dust type & concentration, (5) any acid/oxidizer in the gas stream, (6) emission requirement, (7) quantity. A drawing or sample bag is even better.
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