Glass Fiber Filter Material Types & Properties

What is glass fiber filter material? Glass fiber filter material refers to filter materials made from fiberglass, used for purifying fine particles in the air or filtering impurities in liquids such as water and oil. Common glass fiber filter materials include glass fiber primary, medium, and high-efficiency filter paper, glass fiber woven filter fabric, glass fiber non-woven fabric, and glass wool. They are widely used in dust removal systems, HVAC systems, and oil-gas separation fields.

Raw materials for Glass Fiber Filter Material

Fiberglass is made from quartz sand, limestone, dolomite, paraffin, etc., and is spun with soda ash, boric acid, etc. Its main components are silicon dioxide and certain metal oxides. According to composition and performance, glass fiber can be divided into four categories: alkali-free, medium-acid, high-alkali, and special glass fiber; according to form, it can be divided into continuous glass fiber, chopped glass fiber, and glass wool. Glass fiber features flame retardancy, corrosion resistance, heat resistance, low moisture absorption, low elongation at break, high tensile strength, brittleness, good thermal insulation and chemical stability, and good electrical insulation.

Long glass fibers and short glass fibers

Glass Fiber Production Process

The production processes of glass fiber include the crucible drawing method and the pool kiln drawing method, with the pool kiln drawing being the mainstream process.

Pool kiln drawing method: Talc and limestone are ground into powder and mixed together in a certain ratio. Using natural gas and oxygen as chemical raw materials and electrical energy as the power source, they are burned in a kiln. The combustion temperature is controlled between 1000 °C and 1600 °C. During the combustion process, the mixed powder of talc and limestone melts into a liquid, which flows through a platinum-rhodium precious metal alloy (85:15) porous leak plate and is drawn at high speed into glass primary fibers. These fibers are then condensed with cooling water to form fiberglass. After applying a chemical sizing agent to the surface of the fiberglass, it is dried, packaged, and shipped. The drawing machine is a key piece of equipment in the glass fiber forming process. Its function is to rapidly stretch the glass liquid flowing from the bushing and wind it in a certain direction to form. The performance and precision of the drawing machine directly affect the quality of the fibers.

Schematic diagram of the pool kiln drawing method production process

Features

High strength. Glass fiber has very high tensile and flexural strength, allowing it to withstand significant forces and loads in many applications.
High-temperature resistance. Glass fiber can withstand high-temperature environments, with a high melting point and heat resistance, making it suitable for applications requiring high-temperature resistance.
Corrosion resistance. Glass fiber has excellent corrosion resistance, and can withstand the erosion of acidic and alkaline media and some chemicals, making it widely used in fields such as chemical engineering and environmental protection.
Wear resistance. Glass fiber has high wear resistance and good anti-wear performance, allowing it to maintain a long lifespan in friction and wear environments.
Lightweight. Compared to other materials, Glass fiber is a relatively lightweight material with low density, giving it an advantage in applications where low weight is required.
Insulating properties. Glass fiber is an excellent insulating material with good electrical and thermal insulation properties, and it is widely used in power equipment, electronic devices, and other fields.

Types of Glass Fiber Filter Material

Classified by the form of fiberglass, it is divided into glass fiber filter paper, glass fiber woven filter fabric, and glass fiber non-woven filter fabric. Among them, glass fiber filter paper is mainly applied using the wet-laid process, glass fiber woven filter fabric is produced using weaving methods, and glass fiber non-woven filter fabric (glass fiber non-woven filter fabric) is primarily manufactured by needle punching and wet processes. Strictly speaking, glass fiber filter paper belongs to non-woven filter materials. According to the classification of glass fiber filter materials by use, there are glass fiber exhaust filter materials, glass fiber intake filter materials, and glass fiber liquid filter materials.

Glass Fiber Filter Paper

Glass fiber filter paper is a thin sheet made from fine-diameter fiberglass. It has good dimensional stability, high chemical resistance, strong weather resistance, and good non-flammability. It can be made from 100% glass fiber(with a diameter of 0.3–0.5 μm or less, mainly composed of silicon dioxide), lightly beaten, with adhesive added, or mixed with some chemical wood pulp, and formed on a Fourdrinier or cylinder paper machine.

The production of glass fiber filter paper uses a wet-laid process, similar to the production process of regular filter paper. The difference lies in the fact that glass fiber filter paper undergoes mild pulping because glass fiber is brittle. The raw materials used are 100% ultra-fine glass fiber or a certain proportion of wood pulp fibers.

Various types of glass fiber filter paper stacked together

Glass Fiber Woven Filter Fabric

Glass fiber woven filter fabric is a type of filter material made from glass fibe ror glass fiber expanded yarn, offering good high-temperature resistance, chemical stability, and mechanical strength. Glass fiber woven filter fabric is commonly used in flue gas purification equipment, air filters, and liquid filters to capture solid particles, dust, smoke, and other pollutants, thereby maintaining a clean environment and efficient industrial processes. The raw materials used for glass fiber woven filter fabric include four types: alkali-free glass fiber(long fiber), medium-alkali glass fiber(long fiber), alkali-free glass fiber bulked yarn, and medium-alkali glass fiber bulked yarn.

Table 1: Material and Property List
Material	Temperature Characteristics	Air Permeability	Single Fiber Diameter
Alkali-free glass fiber	It can be used long-term at temperatures up to 280 °C, with instantaneous (within 1 hour) temperature resistance up to 350 °C。	The air permeability of glass fiber expanded yarn filter materials is higher than that of continuous glass fiber filter materials, with glass fiber needle felt materials having the highest air permeability	E-glass fiber can produce fibers with a single fiber diameter of 8–9 μm
Medium-alkali glass fiber	The operating temperature of medium-alkali glass fiber filter materials is only 260 °C, with instantaneous temperature resistance below 300 °C。		--
Alkali-free glass fiber expanded yarn	It can be used long-term at temperatures up to 280 °C, with instantaneous (within 1 hour) temperature resistance up to 350 °C.		--
Medium-alkali glass fiber expanded yarn	The operating temperature of medium-alkali glass fiber filter materials is only 260 °C, with instantaneous temperature resistance below 300 °C.		--

Table 2: Various Glass Woven filter Fabric Surface Chemical Treatment Formulas
Formula Name	Formula Composition	Design Purpose	Applications	Color	Filter Material Properties
FCA (anti-condensation formula)	Mainly composed of water repellent and silicone oil	Designed for dust emission places with high moisture content and low temperature that are prone to condensation	Dust control for cement mills, dryers, etc.	Yellow	Excellent hydrophobicity, good flexural and abrasion resistance
FQ	Mainly based on reactive silicone oil	Provide better dust cleaning performance	Mainly used in cement rotary kilns and carbon black industry, etc.	Yellow	Certain hydrophobicity, good flexural and abrasion resistance
165	Mainly based on graphite	Provide a better cost-performance ratio	Mainly used in the cement industry, etc.	Black	Certain hydrophobicity, flexural and abrasion resistance
FS2 (steel formula)	Mainly based on polytetrafluoroethylene and reactive silicone oil	Designed for blast furnace gas purification in the steel industry	Blast furnace gas purification	Yellow	Certain hydrophobicity, good flexural and abrasion resistance
PSi	Primarily composed of silicone oil, graphite, and polytetrafluoroethylene	Designed for applications with relatively high flue gas temperatures	For dust emission places with high flue gas temperatures in industries like as building materials	Black	Good temperature resistance, flexibility, flexural and abrasion resistance
RH (acid-resistant formula)	Primarily composed of silicone oil, graphite, polytetrafluoroethylene, and acid-resistant components	Provide good acid resistance	Mainly used in cement shaft kilns and the production of 15,000 tons of carbon black	Black	Good hydrophobicity, acid resistance, and flexural and abrasion resistance
TFB (high flexural resistance formula)	Primarily composed of polytetrafluoroethylene	Provide excellent flexural and abrasion resistance	For dust removal from high-temperature flue gases in industries such as cement, carbon black, and waste incineration	Yellow	Good flexural and abrasion resistance, hydrophobic properties, and long service life, with some acid resistance
AR (high acid resistance formula)	Primarily composed of silicone oil, graphite, polytetrafluoroethylene, and acid-resistant components	Provide excellent acid resistance	Dust removal from acidic atmosphere flue gases in coal-fired boilers and waste incinerators	Black	Excellent hydrophobicity, acid resistance, and good flexural and abrasion resistance.
YM (coal-fired boiler formula)	Primarily composed of silicone oil, graphite, polytetrafluoroethylene, and acid-resistant components	Specifically designed for coal-fired boilers	Dust removal from coal-fired boiler flue gas	Black	Excellent hydrophobicity, acid resistance, good flexural and abrasion resistance.
B1	Mainly composed of silicone oil and polytetrafluoroethylene	Designed for the carbon black industry	Pulse dust removal in the carbon black industry	Yellow	Featuring a three-micropore structure, low filtration resistance, and a dust removal efficiency of up to 99.9%. The filtration speed is about twice that of ordinary fabric filter materials.
St		Designed for the steel industry	Blast furnace gas purification	Yellow
Che		Designed for the chemical industry	Gas-solid separation in the chemical industry	Yellow
JF (interwoven filter material formula)	Mainly composed of water repellent and silicone oil	Specifically designed for glass fiber interwoven filter materials	Dust control for cement mills, dryers, etc.	Yellow	In addition to FCA's anti-condensation properties, it has better flexural resistance
F2 (waterproof and oil-proof formula)	Primarily composed of waterproof and oil-proof components	Designed to provide waterproof and oil-proof performance for polyester filter materials	Metallurgy, building materials, etc.	White	Excellent waterproof and oil-proof performance

Weaving Process of Glass Fiber Woven Filter Fabric

Plain Weave

Plain weave is formed by interlacing yarns, with each yarn having one yarn above and one below. Plain weave has good fabric stability.

Twill Weave

Twill weave involves two or more filling yarns interlacing alternately. It is characterized by flexibility, smoothness, and strength, but has relatively poor stability.

Ribbed Weave

Ribbed weave locks the yarns by intercrossing two or more warp threads with one or more weft threads.

4-Shaft Satin Weave

The 4-shaft satin weave more easily adapts to the typical curved surfaces in reinforced plastics.

8-Shaft Satin Weave

The 8-shaft satin weave involves one weft thread floating over seven warp threads and under one warp thread. This weave is very flexible and is used to form curved surfaces.

Double Twill Weave

Double twill weave is used in situations requiring high-density tight weaving. The characteristic of double twill weave is the diagonal or slanting lines.

Glass Fiber Non-Woven Fabric

Fiberglass non-woven filter fabric (non-woven fabric) is a filter material made from glass fiber through a non-woven process. The non-woven process binds fibers together through methods such as wet-laid, needle punching, and melt-blown, unlike traditional weaving processes that interlace fibers. Glass fiber non-woven filter fabric typically has advantages such as high strength, high-temperature resistance, and chemical corrosion resistance, making it suitable for filtration work in harsh environments such as high temperature, high humidity, and corrosive gases. It is widely used in industrial fields such as air filters, liquid filters, automotive filters, etc.

Glass fiber non-woven filter cloth on a white background

Table 3: Material Table
Item	Material Type
Main Material	Alkali-free glass fiber
Main Material	Medium-alkali glass fiber
Composite Material	Polyimide (P84), Polyphenylene Sulfide (PPS), Metas, Polyamide-imide, Polytetrafluoroethylene (PTFE), etc.
Coating	Composite expanded microporous polytetrafluoroethylene film (ePTFE)