Application and Product Promotion of New Carbonized Fiber Fire-Retardant Materials

Preoxidized acrylic fiber, formally known as preoxidized polyacrylonitrile fiber, is a special fiber material made by preoxidizing polyacrylonitrile (PAN) precursor fibers in air at temperatures ranging from 200 to 300°C. This fiber exhibits high-temperature resistance and flame retardancy, remaining stable for extended periods at 300°C and capable of withstanding instantaneous temperatures up to 1000°C.

The above-mentioned flame—this preparation process constitutes the core preliminary step in carbon fiber production. From a molecular structural perspective, the essence of the pre-oxidation process lies in the fact that, under the influence of heat and oxygen, the linear macromolecular chains of PAN undergo a series of complex chemical reactions, including cyclization, dehydrogenation, and oxidation.

The reaction proceeds stepwise, gradually forming a more stable ladder-like structure. This structural transformation imparts to preoxidized silk unique performance characteristics that distinguish it from both the original silk and carbon fibers, making it a high-tech fiber material with exceptional properties. It exhibits excellent chemical stability and is resistant to acids, alkalis, and a wide range of organic substances.

Agent corrosion.

The process parameters for preparing preoxidized fibers are extremely precise and critical; factors such as the heating rate, temperature field uniformity, tension control, and residence time all have a decisive impact on the final product’s performance. Proper process conditions can promote the orderly transformation of the molecular structure and prevent fiber defects.

Excessive shrinkage or the formation of defects is avoided, thereby yielding preoxidized fiber products with outstanding performance. This precisely controlled manufacturing process enables the preoxidized fibers to achieve significantly enhanced thermal stability and mechanical properties while retaining the excellent spinning performance inherent in the PAN precursor fibers. They also exhibit excellent processability.

It is processable and can be made into various forms, such as short fibers, yarns, fabrics, and felts.

In terms of material properties, preoxidized fibers exhibit multiple outstanding characteristics. Their limiting oxygen index (LOI) typically ranges from 35% to 45%, placing them in the category of flame-retardant materials. When exposed to fire, these fibers do not melt, soften, or shrink; they do not produce dripping molten material, but instead undergo carbonization only, thereby preventing secondary damage. Meanwhile, the preoxidized...

Silk also exhibits excellent thermal stability, maintaining consistent performance over a long period in environments ranging from 200 to 300°C, and can withstand even higher temperatures for brief periods. In terms of electrical properties, preoxidized silk begins to show some conductivity, with a volume resistivity falling between that of PAN precursor fibers and carbon fibers. These characteristics...

Sexuality collectively forms the basis for the application of pre-oxidized silk as an independent material.

The morphological categories of preoxidized fibers include fibers and yarns, such as short fibers and continuous filaments; fabrics, including woven fabrics, knitted fabrics, and carbon fabrics; nonwoven materials, such as needle-punched felts, preoxidized fiber felts, and carbon fiber felts; and sealing and preformed components, such as packing (sealing gaskets) and needle-punched preforms.

Manufacturing systems, etc.

Continuous filaments of preoxidized carbon fibers maintain excellent mechanical properties, with tensile strengths reaching 300–500 MPa and moduli around 10–15 GPa. At the same time, these fibers exhibit both flexibility and spinnability, allowing them to be directly used for weaving or as reinforcing materials. Short-cut fibers, on the other hand, come in various lengths.

The product specifications typically range from 3 to 12 mm and are suitable for nonwoven processes or as a filler in composite materials.

The yarn is produced through traditional spinning processes such as twisting, which enhances the fiber’s cohesion and processing performance, making it easier for subsequent weaving operations.

In machine-woven fabrics, plain-weave fabrics have a stable structure and are suitable for use as inner layers in fire-retardant garments and as sealing materials. Twill fabrics have a soft hand feel and are often used as outer fabric layers in protective clothing. Satin fabrics have a smooth surface and are ideal for high-temperature filtration applications.

Knitted fabrics have excellent elongation and elasticity, making them suitable for applications that require high deformability, such as protective gloves, headgear, and other protective equipment with stringent ergonomic requirements.

Felt is a textile material produced by carding short fibers into a web and then consolidating them through needle punching. It features a three-dimensional network structure and is an excellent high-temperature thermal insulation material, capable of withstanding temperatures of 300°C or higher.

Pre-oxidized silk paper is produced via a wet papermaking process and typically has a thickness ranging from 0.1 to 1.0 mm. It boasts excellent electrical insulation properties and thermal resistance, making it an ideal insulating material for high-end electrical equipment.

The following materials are available for preoxidized carbon fiber composites:

Preoxidized carbon fiber-reinforced resin materials combine the heat resistance of preoxidized carbon fibers with the ease of molding provided by resins. They are manufactured into various heat-resistant structural components through processes such as compression molding and pultrusion, and find applications in fields including transportation and electronics. These composite materials typically exhibit performance at temperatures ranging from 150 to 200°C.

It can be used long-term under these conditions, emits low smoke and has low toxicity when burned, demonstrating excellent environmental friendliness.

Preoxidized silk-reinforced rubber fabric is primarily used in high-performance sealing products, such as engine gaskets and blowout preventers for oilfields—high-temperature resistant seals. The strong interfacial bond formed between the preoxidized silk and the rubber matrix ensures the sealing reliability of the composite material under high-temperature and high-pressure conditions.

Preoxidized carbon fiber-metal composites are functional materials prepared by a special process that combines preoxidized carbon fibers with low-melting-point metals, endowing them with both metallic thermal conductivity and the high-temperature resistance of preoxidized carbon fibers. These composites show promising application potential in the field of thermal management.

Pre-oxidized silk composite nonwoven fabric with adhesive backing—by using a high-temperature, double-sided adhesive lamination process, one side of the nonwoven fabric gains the advantage of easy adhesion.

Pre-oxidized silk composite aluminum foil nonwoven fabric—aluminum foil has the property of reflecting thermal radiation. The composite aluminum foil felt can be used in applications such as fire masks and fire curtains.

Preoxidized silk-silicone composite fabric: This fabric uses preoxidized silk woven fabric as the base material, with a silicone layer laminated on one or both sides. It combines the high-temperature dimensional stability of the base fabric with the elasticity and sealing properties of the silicone layer, allowing it to be fabricated into complex shapes. It is suitable for use in high-temperature pipe flexible compensators and fire-resistant barriers for specialized equipment.

Thermal covers, ultra-soft thermal gaskets.

Pre-oxidized carbon fiber composite aerogel felt boasts low thermal conductivity, lightweight properties, flexibility, and excellent mechanical strength—all of which make it an ideal thermal insulation and fire-retardant material for use within the power battery packs of new-energy vehicles, effectively delaying heat propagation.

Pre-oxidized silk-aromatic polyamide composite fabric—aromatic polyamide fibers are blended into the yarn to compensate for the brittleness of pre-oxidized silk, thereby enhancing the fabric’s strength and abrasion resistance. This fabric can be produced in colored varieties. It is suitable for high-grade fire-fighting suits, special operations uniforms, military and police protective gear, and high-temperature industrial aprons—applications that demand exceptional strength and durability.

Seeking extremely high-performance protective clothing.

Pre-oxidized silk-composite polyimide fabric, while maintaining high flame retardancy, also imparts excellent thermal stability across a wide temperature range. It is suitable for interior linings of aerospace vehicles, specialized fire-fighting suits, protective gear for extreme environments (such as deep space and polar regions), high-temperature filtration, and other applications where both temperature resistance and flame retardancy are critical.

The realm of extreme demands.

Application of a New Type of Carbonized Fiber Fire-Retardant Material

1. Construction field

① Exterior wall thermal insulation and fire protection

In building exterior wall insulation systems, pre-oxidized silk fire-resistant cotton can be used as a fire-retardant protective material for the insulation layer. When installed between the insulation material and the exterior wall decorative layer, it can effectively prevent the spread of fire in the event of a fire, protect the insulation material from combustion, and enhance the fire resistance of the building’s exterior wall.

Fire safety.

② Fire-resistant wrapping for steel structures

For steel structural components in buildings, such as steel beams and steel columns, pre-oxidized fiber fire-resistant cotton can be used for wrapping. At high temperatures, the strength of steel structures rapidly decreases. Pre-oxidized fiber fire-resistant cotton boasts excellent thermal insulation properties, which can slow down the rate of temperature rise in steel structures during a fire and thereby extend the structural integrity of the steel.

The fire resistance rating of a structure provides more time for personnel evacuation and firefighting rescue operations. In industrial plants and large commercial buildings, this approach is commonly used to protect steel structures against fire.

Protect.

③ Fire-resistant partition

Inside the building, fire-resistant partitions can be constructed using pre-oxidized silk fireproof cotton. By installing this material in areas requiring fire separation—such as stairwells, elevator shafts, cable shafts, and other spaces adjacent to neighboring areas—it can effectively prevent the spread of fire and smoke, isolate the source of the fire, and ensure the safety of the building.

The safety of life and property of personnel inside the structure.

④ Pipe fire protection

Various pipelines within a building—such as ventilation ducts and cable conduits—can be fire-protected by filling the space around them with pre-oxidized fiber fire-resistant cotton when they pass through firewalls or fire compartments, thereby preventing fire from spreading via these pipelines.

2. Personal Protective Equipment field

In the field of fire protection, preoxidized silk products play an irreplaceable role. Fire-resistant clothing is the most traditional application area for preoxidized silk, encompassing firefighter uniforms, industrial protective garments, and military protective gear, among others. When exposed to flames, preoxidized silk fabrics form a dense carbonized layer that effectively...

It blocks thermal conduction, providing users with valuable time to escape. Modern high-performance fire-resistant suits typically feature a multi-layer composite structure made of pre-oxidized fibers combined with other fibers such as flame-retardant viscose and aramid, balancing protective performance with wearing comfort.

Emergency rescue products such as fire blankets and escape ropes represent another important application of preoxidized fiber. Preoxidized fiber fire blankets have a high limiting oxygen index and are non-combustible, making them essential safety equipment for homes, factories, and public spaces. The outstanding performance of preoxidized fiber products in these applications is primarily attributable to their:

Inherently flame-retardant properties and dimensional stability at high temperatures.

3. Fireproof and Thermal Insulation Field

Pre-oxidized spunbond needle-punched filter bags can operate continuously in environments above 200℃ and withstand instantaneous temperatures up to 260℃. They also exhibit excellent resistance to chemical corrosion and are used in flue gas purification systems for industries such as coal-fired boilers, waste incineration, and cement production. Compared with conventional polyester filter media,

Pre-oxidized fiber filter media boasts a longer service life and more stable filtration efficiency under high-temperature conditions, and features a smooth surface with excellent dust-cleaning performance.

In the field of building fire-resistant materials, preoxidized filament nonwoven fabrics and felt products are used for fireproof coatings on steel structures and as fire-resistant seals for doors and windows. During a fire, these materials can effectively slow down the temperature rise in structural elements, thereby buying crucial time for evacuating personnel and facilitating firefighting and rescue operations.

In industrial thermal insulation, pre-oxidized fiber felts and blankets are used for thermal insulation of various industrial furnaces, high-temperature pipelines, and equipment. Pre-oxidized fiber materials exhibit particularly outstanding thermal insulation performance in the medium- and low-temperature range (200–600℃), featuring low thermal conductivity and small thermal capacity, which can effectively reduce energy consumption.

Energy consumption in the industry. In the aerospace field, preoxidized carbon fiber composites are used in thermal protection systems to shield structural components from aerodynamic heating. These applications fully leverage the combined advantages of preoxidized carbon fibers—lightweight, high-temperature resistance, and low thermal conductivity.

4. Sealing and Friction Field

① Pre-oxidized fiber-reinforced rubber seals are used in automotive engines, transmissions, and exhaust systems, and can maintain elasticity and sealing performance even under sustained high-temperature conditions.

② In the petrochemical industry, pre-oxidized filament woven packing is used for sealing pumps and valves, capable of withstanding the dual challenges of corrosive media and high temperatures. It is also used in high-temperature conveyor belts and exhibits flame-retardant properties when employed underground in coal mines.

③ In the field of friction materials, preoxidized fibers are used as reinforcing fibers to manufacture high-performance brake pads. The coefficient of friction remains stable at 0.35–0.45, and the wear resistance is more than 40% higher than that of metal materials—particularly suitable for heavy-duty vehicles and high-temperature operating conditions. Preoxidized fiber friction materials exhibit excellent friction properties.

Advantages include stable coefficients, low wear rate, no thermal fade, and low noise.

④ In terms of safety protection for new-energy vehicles, the battery pack’s thermal insulation layer uses pre-oxidized fiber aerogel, which effectively prevents the spread of thermal runaway from individual cells and can withstand instantaneous high temperatures up to 1000℃.

⑤ In the fields of rail transit and aerospace, preoxidized filament nonwoven fabrics are high-temperature resistant, fire-retardant, produce low smoke levels, and are lightweight. They are used as fire-resistant layers for automotive and high-speed train seats, as well as thermal insulation materials for aircraft engines.

E-mail:
gdkaidun@163.com

Phone/WeChat:
86-131-3828-6677

Address:
Room 401, Building 21, No. 1, Keqing Road, Yundonghai Street, Sanshui District, Foshan City, Guangdong Province