Aerogel felt, as one of the most attention-grabbing new materials in the insulation industry in recent years, is increasingly being applied in various fields such as building energy conservation, industrial pipeline insulation, LNG projects, and petrochemical equipment insulation due to its ultra-low thermal conductivity, lightweight flexibility, high temperature resistance, and water repellency. For engineering designers and procurement personnel, understanding the core "technical parameters" of aerogel directly determines whether a project can achieve energy-saving, safety, and durability targets. This article will systematically interpret aerogel from multiple perspectives, including material structure, thermal conductivity, flame retardancy, water vapor permeability, temperature resistance, mechanical properties, and construction adaptability.

I. Material Structural Parameters: Nanoporous Structure is the Core Foundation of Performance

Aerogel is a nanoporous solid material with a pore size typically ranging from 20 to 50 nm. This structure endows it with extremely low solid thermal conductivity. Fiber-reinforced aerogel felt is usually formed by aerogel particles attached to substrates such as glass fiber and PET fiber, and the overall density can be adjusted within the range of 120–180 kg/m³.

Key Structural Parameters:

Nanopore Size: 20–50 nm

Porosity: >90%

Density: 120–180 kg/m³

Material Forms: Rolls, sheets, strips, etc.

This fiber-reinforced structure makes aerogel more stable than brittle pure aerogel and more suitable for on-site construction.

II. Thermal Conductivity: The Most Core Technical Parameter of Aerogel

Thermal conductivity (λ) is a key indicator for evaluating the performance of insulation materials. Aerogels generally have lower thermal conductivity than traditional insulation materials, which is one of the reasons they are considered "high-performance insulation materials."

Thermal conductivity of conventional aerogel felt:

0.018–0.023 W/m·K (25℃)

Comparison with traditional materials:

Glass wool: 0.035–0.040

Rock wool: 0.035–0.045

Rubber and plastic: 0.032–0.036

At the same thickness, aerogel has superior thermal insulation performance compared to conventional insulation materials, thus offering advantages in projects requiring higher insulation performance and with limited space.

III. Temperature resistance: Adaptable to various working conditions

Aerogel felt can achieve different temperature resistance levels depending on the substrate and process.

Typical Temperature Range:

-200℃ ～ +650℃

Different models are available:

Low Temperature Type (-200℃ to +200℃): Used for LNG cold energy applications and refrigeration pipelines

Normal Temperature Type (-50℃ to +400℃): Building insulation and air conditioning systems

High Temperature Type (up to +650℃): Petrochemical, power, and boiler external insulation

This allows aerogels to cover applications ranging from extremely low temperature cold pipes to high temperature equipment.

IV. Hydrophobicity and Moisture Absorption: Key to Maintaining Long-Term Thermal Insulation Performance

Aerogels have strong hydrophobicity, which is especially important for cold pipe systems.

Different Types of Hydrophobicity:

Hydrophobicity ≥ 98% (Standard Type)

High-temperature aerogels are typically hydrophilic (for easy moisture removal)

Low moisture absorption reduces the increase in thermal conductivity caused by water absorption, extending material life.

V. Compression Resistance and Flexibility: Strong Construction Adaptability

Although aerogel felt boasts strong performance, it maintains excellent flexibility, adapting to complex bends, valves, flanges, and other locations.

Mechanical Performance Parameters:

Compressive Strength: ≥0.25MPa

Tensile Strength: ≥0.4MPa

Flexible felt can withstand multiple bends without breaking.

Advantages of flexible aerogel felt include:

Easy to cut

Can cover irregular equipment

Reduces the number of seams

Suitable for insulation in confined spaces

VI. Combustion Performance: Multiple models meet Class A non-combustible standard

As an inorganic material, aerogel itself possesses very high fire resistance.

Common Flame Retardant Properties:

Combustion Performance Rating: A1 (Non-combustible)

Low smoke, no molten droplets

Therefore, it is suitable for building and industrial scenarios with specific fire protection requirements.

VII. Water Vapor Permeability: Maintaining Long-Term Stability of Cold Piping Systems

For chilled water pipes and LNG pipelines, water vapor permeability is a key parameter. Aerogel felt water vapor permeability coefficient:

≤5.0 × 10⁻¹¹ kg/(m·s·Pa)

The low permeability effectively reduces condensation and lowers the risk of corrosion.

VIII. Long-term performance and aging stability

Aerogel materials exhibit extremely high long-term stability:

No powdering

No shrinkage

No deformation

Strong UV resistance

Under normal conditions, its lifespan can reach 20–25 years or more.

Aerogel, with its ultra-low thermal conductivity, wide temperature range, high hydrophobicity, A1-grade non-combustible properties, flexible construction adaptability, and long lifespan, has become the preferred material for high-end thermal insulation projects. Understanding its technical parameters helps engineering units, procurement personnel, and designers more accurately match application scenarios, improving project quality and energy efficiency.