A Nomex Filter Bag, also known as an Aramid Filter Bag, is a high-temperature industrial dust collector filter bag made from aramid fiber (polyamide aromatic fiber). It is widely used in baghouse dust collectors, pulse jet cleaning systems, and high-temperature filtration applications where polyester and acrylic filter bags cannot withstand operating conditions.
Nomex® is a registered trademark of DuPont Nomex, and aramid fibers are known for their excellent heat resistance, mechanical strength, and dimensional stability.
Main Features of Nomex (Aramid) Filter Bags
1. Excellent High-Temperature Resistance
The biggest advantage of Nomex filter bags is their ability to operate continuously at elevated temperatures.
Typical performance:
| Parameter | Specification |
|---|---|
| Material | 100% Aramid (Nomex) Fiber |
| Filter Type | Needle-punched Felt |
| Continuous Working Temperature | 180–200°C |
| Short-Term Peak Temperature | Up to 220°C |
| Weight | 450–600 g/m² |
| Cleaning Method | Pulse Jet Cleaning |
| Filtration Efficiency | High |
(Temperature limits depend on gas composition, humidity, and filter finishing.)
2. Excellent Mechanical Strength
Aramid fiber has high tensile strength and good abrasion resistance.
Benefits:
- Longer filter bag service life
- Better resistance to dust abrasion
- Suitable for high airflow applications
- Maintains shape under continuous operation
This makes Nomex filter bags suitable for heavy-duty industrial dust collectors.
3. Good Chemical Resistance
Nomex filter media provides good resistance to many industrial gases and chemicals.
It performs well in environments containing:
- Hot flue gas
- Acidic dust
- Organic solvents
- Industrial fumes
However, prolonged exposure to strong alkalis, oxidizing chemicals, or high-temperature moisture may reduce service life.
4. Excellent Dimensional Stability
At high temperatures, some filter materials shrink or deform. Nomex fiber maintains better dimensional stability, helping:
- Maintain proper bag size
- Prevent bag deformation
- Improve sealing performance
- Reduce maintenance frequency
Applications of Nomex Filter Bags
Nomex (Aramid) filter bags are commonly used in:
Asphalt Mixing Plants
- Asphalt drum dryers
- Hot aggregate dust collection
- Asphalt plant baghouses
Cement Industry
- Cement grinding systems
- Clinker cooling dust collection
- High-temperature exhaust filtration
Steel Industry
- Furnace dust extraction
- Metal processing fumes
- Foundry dust collectors
Chemical Industry
- High-temperature process filtration
- Chemical powder recovery
Waste Incineration
- Hot flue gas filtration
- Industrial waste treatment systems
Nomex Filter Bag Structure
A typical Nomex filter bag consists of:
1. Aramid Needle Felt Layer
Provides filtration and dust capture.
2. Surface Finishing Treatment
Common treatments include:
- Singeing
- Heat setting
- Calendering
- Water and oil repellent treatment
3. Supporting Components
- Carbon steel or stainless steel filter cage
- Snap band / flange top
- Sewn or welded bottom construction
Nomex vs Other Filter Bag Materials
| Feature | Nomex (Aramid) | Acrylic | Polyester | PPS |
|---|---|---|---|---|
| Temperature Resistance | ★★★★★ | ★★★ | ★★ | ★★★★ |
| Moisture Resistance | Good | Excellent | Poor | Excellent |
| Acid Resistance | Good | Good | Moderate | Excellent |
| Alkali Resistance | Moderate | Good | Good | Excellent |
| Mechanical Strength | Excellent | Good | Good | Excellent |
| Cost | High | Medium | Low | High |
Nomex Filter Bag Maintenance Tips
To maximize service life:
- Control operating temperature
- Avoid exceeding recommended limits.
- Prevent condensation
- Water combined with high-temperature acidic gases can damage fibers.
- Optimize pulse cleaning
- Excessive cleaning pressure may shorten bag life.
- Monitor pressure drop
- Abnormal pressure increase may indicate dust blockage or bag damage.
How to Select a Nomex Filter Bag
Before ordering, confirm:
- Filter bag diameter and length
- Filter media weight
- Operating temperature
- Dust characteristics
- Gas chemical composition
- Cleaning method
- Filter cage dimensions
- Required filtration efficiency
Conclusion
Nomex (Aramid) Filter Bags are a premium high-temperature filtration solution designed for demanding industrial dust collection systems. With excellent heat resistance, strong mechanical properties, and good chemical stability, they are widely used in asphalt plants, cement factories, steel mills, and other industries requiring reliable high-temperature dust filtration.
For high-temperature pulse jet baghouse systems, Nomex filter bags provide a balance of temperature resistance, durability, and filtration efficiency, making them one of the most trusted filter media choices for harsh industrial environments.
