How do the inorganic properties of glass microfiber endow filter paper with excellent high-temperature resistance and flame retardant properties?
Release Time : 2026-02-05
In fields with stringent requirements for filtration material performance, such as air purification, biosafety, industrial dust removal, and new energy batteries, filter paper made from glass microfiber has become an irreplaceable core material due to its superior high-temperature resistance and inherent flame retardancy. This advantage does not stem from added chemical additives, but is rooted in its inorganic silicate nature—from atomic structure to macroscopic properties, glass microfibers inherently possess the ability to resist thermal decomposition and flame erosion, providing reliable protection for air filtration in high-risk environments.
1. Inorganic Network Structure: The Cornerstone of Chemical Stability at High Temperatures
The main components of glass microfiber are inorganic oxides such as silicon dioxide, alumina, and calcium oxide. These are melted at high temperatures and then centrifugally spun into ultrafine fibers with a diameter of 0.5–5 micrometers. Internally, it forms a three-dimensional continuous amorphous silicon-oxygen tetrahedral network with high chemical bond energy and contains no organic elements such as hydrocarbons. This means that when heated, the material will not undergo the pyrolysis, carbonization, or release of flammable gases common in organic polymers. Even during long-term operation at 300–500℃, or short-term exposure to temperatures above 700℃, glass microfiber filter paper maintains its structural integrity and filtration efficiency without decline, far exceeding that of organic filter materials such as polypropylene and PET.
2. Intrinsically Flame Retardant: Self-Extinguishing Properties Without Additives
In terms of flame retardancy, glass microfiber filter paper is a Class A non-combustible material. Because it contains no flammable components, it neither burns nor supports combustion when exposed to an open flame, and it does not produce molten droplets or toxic fumes. When a flame comes into contact with the filter paper surface, the heat is rapidly conducted and dispersed, and the material itself may only undergo localized softening, but will never ignite sustained combustion. This "intrinsically safe" characteristic makes it widely used in scenarios with zero tolerance for fire risks, such as nuclear power plant ventilation systems, aircraft cabin air circulation, and medical negative pressure isolation wards, avoiding the risks associated with traditional flame-retardant filter materials due to additive precipitation, aging failure, or the release of halogen toxic gases during combustion.
3. Thermal Dimensional Stability: Ensuring Filtration Accuracy Under High-Temperature Conditions
In addition to heat resistance and flame retardancy, glass microfiber filter paper exhibits an extremely low coefficient of thermal expansion under temperature changes, far lower than that of organic fibers. This means that in alternating hot and cold environments or high-temperature environments, the filter paper is less prone to shrinkage, warping, or pore structure collapse, thus maintaining a stable pore size distribution and filtration efficiency. For example, in automotive cabin air conditioning filters, where summer engine compartment temperatures can reach over 100°C, the glass fiber filter layer still ensures efficient interception of PM2.5, pollen, and other particles; in industrial flue gas filtration, even when facing dust-laden airflows exceeding 200°C, the filter paper can operate stably for extended periods, avoiding bypass leakage due to deformation.
4. Synergistic Reinforcement: Balancing Strength and Environmental Safety
Although pure glass fiber is relatively brittle, through optimized composition and the use of a wet-laid process to form a dense three-dimensional network, modern glass microfiber filter paper possesses sufficient mechanical strength to meet the requirements of winding, folding, and installation. Simultaneously, its production process does not use adhesive resins, avoiding the problem of organic adhesives carbonizing and clogging pores at high temperatures. More importantly, waste filter paper can be safely landfilled or recycled for glass regeneration, posing no risk of persistent organic pollutants, aligning with green manufacturing trends.
The high-temperature resistance and flame-retardant properties of glass microfiber filter paper are inherent characteristics of the material, not merely functional additions. With its inorganic structure, it builds an invisible firewall, silently protecting air safety in environments with high temperatures, high risks, and high cleanliness requirements. In today's world, where energy transition and public health are increasingly important, this inherently reliable filtration material is becoming an indispensable cornerstone of high-end air treatment systems.
1. Inorganic Network Structure: The Cornerstone of Chemical Stability at High Temperatures
The main components of glass microfiber are inorganic oxides such as silicon dioxide, alumina, and calcium oxide. These are melted at high temperatures and then centrifugally spun into ultrafine fibers with a diameter of 0.5–5 micrometers. Internally, it forms a three-dimensional continuous amorphous silicon-oxygen tetrahedral network with high chemical bond energy and contains no organic elements such as hydrocarbons. This means that when heated, the material will not undergo the pyrolysis, carbonization, or release of flammable gases common in organic polymers. Even during long-term operation at 300–500℃, or short-term exposure to temperatures above 700℃, glass microfiber filter paper maintains its structural integrity and filtration efficiency without decline, far exceeding that of organic filter materials such as polypropylene and PET.
2. Intrinsically Flame Retardant: Self-Extinguishing Properties Without Additives
In terms of flame retardancy, glass microfiber filter paper is a Class A non-combustible material. Because it contains no flammable components, it neither burns nor supports combustion when exposed to an open flame, and it does not produce molten droplets or toxic fumes. When a flame comes into contact with the filter paper surface, the heat is rapidly conducted and dispersed, and the material itself may only undergo localized softening, but will never ignite sustained combustion. This "intrinsically safe" characteristic makes it widely used in scenarios with zero tolerance for fire risks, such as nuclear power plant ventilation systems, aircraft cabin air circulation, and medical negative pressure isolation wards, avoiding the risks associated with traditional flame-retardant filter materials due to additive precipitation, aging failure, or the release of halogen toxic gases during combustion.
3. Thermal Dimensional Stability: Ensuring Filtration Accuracy Under High-Temperature Conditions
In addition to heat resistance and flame retardancy, glass microfiber filter paper exhibits an extremely low coefficient of thermal expansion under temperature changes, far lower than that of organic fibers. This means that in alternating hot and cold environments or high-temperature environments, the filter paper is less prone to shrinkage, warping, or pore structure collapse, thus maintaining a stable pore size distribution and filtration efficiency. For example, in automotive cabin air conditioning filters, where summer engine compartment temperatures can reach over 100°C, the glass fiber filter layer still ensures efficient interception of PM2.5, pollen, and other particles; in industrial flue gas filtration, even when facing dust-laden airflows exceeding 200°C, the filter paper can operate stably for extended periods, avoiding bypass leakage due to deformation.
4. Synergistic Reinforcement: Balancing Strength and Environmental Safety
Although pure glass fiber is relatively brittle, through optimized composition and the use of a wet-laid process to form a dense three-dimensional network, modern glass microfiber filter paper possesses sufficient mechanical strength to meet the requirements of winding, folding, and installation. Simultaneously, its production process does not use adhesive resins, avoiding the problem of organic adhesives carbonizing and clogging pores at high temperatures. More importantly, waste filter paper can be safely landfilled or recycled for glass regeneration, posing no risk of persistent organic pollutants, aligning with green manufacturing trends.
The high-temperature resistance and flame-retardant properties of glass microfiber filter paper are inherent characteristics of the material, not merely functional additions. With its inorganic structure, it builds an invisible firewall, silently protecting air safety in environments with high temperatures, high risks, and high cleanliness requirements. In today's world, where energy transition and public health are increasingly important, this inherently reliable filtration material is becoming an indispensable cornerstone of high-end air treatment systems.