What's Air Filter Microfiber Nonwoven？

Air Filter Microfiber Nonwoven refers to a high-efficiency functional nonwoven fabric designed for air purification, which uses microfiber (≤0.8 denier/0.89 dtex) as the core filtering medium. It integrates the structural advantages of microfibers—large specific surface area, dense porous structure, and strong adsorption capacity—with precise filtering performance, enabling efficient capture of fine particles (PM2.5, dust, aerosols) while maintaining low air resistance. It is widely used in industrial flue gas treatment, medical protection, automotive air filtration, and civil air purification, aligning with the high-performance product system of our microfiber nonwoven export business.

What’s The Characteristics of Air Filter Microfiber Nonwoven?

1  High Filtration Efficiency: Meets international standards such as EN779 (EU) and ASHRAE (US), covering primary (G1–G4) to ultra-high efficiency (H10–U17) levels . It can achieve ≤5mg/m³ ultra-low emission for industrial flue gas and ≥95% filtration rate for 0.3μm particles (N95/KN95 level) for medical use .

2  Low Resistance & High Dust Holding Capacity: The gradient structure (surface ultra-fine layer + middle fine fiber layer + bottom supporting layer) ensures low air resistance (＜0.13 atmospheric pressure for high-efficiency products) , while the porous structure provides large dust holding space, extending service life.

3  Durability & Environmental Adaptability: Adopts needle-punching/water-jetting reinforcement technology, with density ≥1300 needles/m² for structural stability . It resists high temperature (up to 80℃ for conventional products), corrosion, and moisture, and is free of glass fiber breakage risks (safer than traditional glass fiber filters) .

4 Compliance & Safety: Meets REACH, RoHS, and FDA standards. Medical-grade products comply with YY 0469-2011 (surgical masks) and GB2626 (KN95), with non-toxic, non-irritating properties and no secondary pollution .

How to select suitable microfiber for Air Filter Microfiber Nonwoven?

Selecting the right microfiber for air filter nonwovens is a systematic process centered on balancing filtration efficiency, air permeability, and service life, while matching the specific demands of target application scenarios (industrial flue gas treatment, medical protection, automotive HVAC, etc.). The selection must focus on fiber properties, structural compatibility, functional adaptability, and international compliance standards. Below is a detailed, actionable guide:

Prioritize Fiber Fineness & Morphology (Core for Filtration Performance)

Fiber fineness directly determines the filter’s pore size, specific surface area, and particle-capturing capability—the two key metrics for air filters are high filtration efficiency and low air resistance.

Fineness range selection

For high-efficiency filtration scenarios (medical N95/KN95 masks, cleanroom Class 1000+ filters, PM2.5 air purifiers): Choose 0.1–0.5 denier island-in-sea bicomponent microfibers. The ultra-fine fiber diameter (≤5μm) forms a dense, tortuous pore structure, which efficiently traps sub-micron particles (0.3–1μm) via mechanical interception, Brownian motion adsorption, and electrostatic attraction.

For medium-efficiency filtration scenarios (automotive cabin filters, commercial HVAC filters): Select 0.5–0.8 denier microfibers. This balances filtration efficiency (≥80% for PM10) and low air resistance (＜15 Pa at 30 L/min airflow), avoiding excessive energy consumption for ventilation systems.

For industrial coarse filtration scenarios (factory dust removal, flue gas pre-filtration): Optional 1.0–1.5 denier microfibers as the supporting layer, paired with ultra-fine fiber surface layers to form a gradient structure.

Fiber morphology selection

Continuous filament microfibers: Preferred for precision filtration (medical, cleanroom). The continuous structure avoids fiber shedding during use, preventing secondary pollution of filtered air or precision equipment. It is suitable for needle-punched or water-jet nonwoven processes.

Staple microfibers: Suitable for industrial high-dust-holding filters. The crimped staple fibers can form a fluffy structure, increasing dust storage capacity and extending filter service life. Note: Ensure fiber length (38–51mm) to avoid fiber detachment in high-airflow environments.

2. Optimize Fiber Composition & Structure (Ensure Durability & Adaptability)

The chemical composition of microfibers determines their resistance to temperature, chemicals, and moisture—critical for harsh application scenarios.

Core composition: Island-in-sea bicomponent fibers

Prioritize PET (sea phase) + PA (island phase) bicomponent microfibers (typical ratio 7:3 or 8:2). After alkali reduction treatment, the PET phase dissolves, releasing the PA ultra-fine fibers to form a high-performance filtration layer.

PA (nylon) fibers: Offer excellent flexibility, chemical resistance (resistant to weak acids/bases), and electrostatic adsorption capacity (easy to charge via electret treatment), ideal for medical and civil filtration.

PET (polyester) fibers: Provide high thermal stability (resistant to 120–150℃ high temperatures) and mechanical strength, suitable for industrial high-temperature flue gas filtration.

Alternative for special scenarios: Modified PP (polypropylene) microfibers for melt-blown filters, with better hydrophobicity and low resistance, but lower thermal stability than PET+PA fibers.

Gradient structure design (key to balancing efficiency & resistance)

Avoid single-layer uniform fiber structure. Instead, adopt a multi-layer gradient structure:

Surface layer: 0.1–0.5 denier ultra-fine fibers (high filtration efficiency).

Middle layer: 0.5–0.8 denier fibers (dust storage buffer).

Bottom layer: 1.0–1.5 denier coarse fibers (mechanical support, reducing overall air resistance).

This structure can increase dust holding capacity by 30–50% compared to single-layer filters.

3. Match Fiber Properties to End-Use Scenarios (Customized Selection)

Tailor fiber selection to the specific environmental and functional requirements of different application fields: