P84 Filter Bags

 Product Introduction 

The domestic P84 filter bag takes polyimide fiber (code P84) as the core material and is made into a three-dimensional mesh structure filter felt through the needling process. The surface can be compounded with ePTFE (expanded polytetrafluoroethylene) film to form a coated filter material. Its core function is to intercept fine dust (such as PM2.5) in high-temperature flue gas, and it is suitable for continuous high-temperature working conditions of ≤260℃ (instantaneous temperature resistance 300℃). During the process of localization, enterprises in Yancheng, Jiangsu and other places (such as Yancheng Shibang Fabric Industry and Jiangsu Quanzhan Environmental Protection) have achieved mass production by introducing fiber raw materials from the Austrian LENZING Company and combining their own needling and laminating processes, thus breaking the foreign monopoly.

 Product Features 

High-temperature resistance

• It can withstand a long-term temperature of 260℃, with an instantaneous peak temperature of 300℃. It does not decompose and carbonize until above 400℃, far exceeding polyester/polypropylene filter materials.

• Strong thermal stability: The thermal shrinkage rate at 240℃ is ≤1.5%, ensuring high-temperature dimensional stability.

High-efficiency filtration structure

• Irregular fiber cross-section: The irregular veil-like structure increases the specific surface area by 80%, providing more micropores (pore diameters 0.1-3.5μm), and the PM2.5 capture efficiency is ≥99.99%.

• Surface filtration mechanism: Dust only stays on the surface and does not penetrate into the interior, reducing the operating pressure difference (stabilized at 800-1200Pa).

Chemistry and Environmental adaptability

• Corrosion resistance: It can withstand acidic and alkaline environments with a pH range of 2 to 12. Its ability to resist acidic waste gas has been verified in waste incineration.

• Functional post-treatment: Optional PTFE coating (anti-adhesion), nano-titanium dioxide coating (photocatalytic decomposition of organic matter), anti-static treatment, etc.

Physical properties

• High strength: The breaking strength of the base fabric is ≥800N/5cm in the warp direction and ≥1300N/5cm in the weft direction.

• Low resistance and energy saving: The air permeability is 13-16m³/m²·min, which reduces the energy consumption of the fan by 15-35% compared with traditional filter bags.

 Application scenarios 

Industry compatibility and typical working conditions

P84 solution for Core challenges in industry application scenarios

Waste incineration fly ash captures acidic gases + high-temperature PTFE coating + anti-hydrolysis treatment

Gradient composite ePTFE film anti-clogging bags for high-humidity and high-alkali dust in the flue gas at the tail end of cement production kilns

Steel and metallurgy electric arc furnace/converter smoke dust metal dust + high-temperature oxidation wear-resistant base fabric + anti-static coating

Coal-fired power boiler exhaust gas dust removal: High-sulfur flue gas + fine particulate matter coated filter material (emission ≤5mg/m³)

Chemical catalyst recovery: Strong corrosive aerosol P84/PTFE blend + acid-resistant treatment

Note: In the food/pharmaceutical field, FDA/GMP certification is required, and a silicone-free sewing process should be adopted to avoid contamination.

 Product Advantages 

Lifespan and Economy

• The service life is 4 to 6 years (2 to 3 years for ordinary filter bags), and the replacement cost is reduced by 40%.

• The 600MW power plant saves over 600,000 yuan in electricity annually, and the added value of dust recovery reaches 1.2 million yuan per year.

Environmental compliance

• The emission concentration is ≤5mg/m³, exceeding the national standard limit (for example, ≤10mg/m³ in the cement industry).

• Flame retardancy (LOI≥30) reduces the risk of fire and supports the "dual carbon" goals.

Customization flexibility

• Domestic manufacturers support non-standard sizes (diameter ø120-180mm, length 1-10m) and custom-made irregular-shaped bags.

 Customization Process 

Demand confirmation (3-5 working days)

Provide working condition parameters: temperature range, dust composition (such as sulfur content), filtration accuracy (0.5-200μm), and the size of the flower plate holes

Materials and Process Design (1-2 weeks)

Base material selection: Pure P84 needled felt or blended (such as P84/ glass fiber, P84/PTFE).

Post-treatment solutions: Film coating (pore size 0.2-3μm), water and oil repellency, anti-static, etc.

Sample and verification (2 weeks)

Make sample bags → Seal performance test (0.3MPa pressurization) → Tensile strength inspection → On-site bag hanging test.

Mass production and delivery (3-4 weeks)

It adopts a three-needle six-thread sewing process (with a longitudinal stitch size of ≥15 stitches per 10cm), and the bag opening has three anti-lock edges.

 Technical AdvantagesQuality Inspection Procedures (in Accordance with GB/T 6719-2009 and ISO 11057) 

Three-stage control system

Raw material inspection

Fiber identification (infrared spectroscopy verification of polyimide structure), gram weight (500±50g/m²), thickness (2.0-2.5mm).

PTFE coating integrity: Microscopic observation of pore size distribution (bubble point method ISO 4003).

Production process monitoring

Needling uniformity: The density of the felt layer is detected by a laser particle size analyzer.

High-temperature setting: The thermogravimetric analyzer (TGA) verified that the shrinkage rate at 240℃ is ≤1.5%.

Finished product testing

Physical properties

Breaking strength (warp direction ≥800N/5cm, weft direction ≥1300N/5cm).

Air permeability (3-15cm³/cm²/s @200Pa).

Functional testing

Sealing performance: No leakage after holding at 0.3MPa for 5 minutes (Labthink sealing instrument).

Corrosion resistance: Strength retention rate ≥85% after soaking in 10% H₂SO₄/NaOH for 72 hours.

Dust cleaning effect: According to the VDI3926 standard dust loading curve test, the peeling rate is over 95%.

 Summary 

Domestic P84 filter bags have become the core choice for industrial dust removal upgrades due to their high-temperature resistance, special-shaped fiber structure, and full life cycle cost advantages. Enterprises in Yancheng, Jiangsu and other places have promoted the substitution of domestic filter materials for imported ones in high-temperature and high-corrosion scenarios such as waste incineration, cement and steel through membrane composite technology (such as ePTFE gradient layer) and recycling process (the pyrolysis recovery rate of used filter bags is 98%). Customization should focus on working condition parameters and post-treatment processes, and quality inspection should cover raw material identification to dynamic filtration performance verification.