Spunlace nonwoven of pre-oxygenated fiber
Segment market:
Characteristics of Pre-Oxygenated Fiber:
· Ultimate Flame Retardancy: The limit oxygen index (LOI) is usually > 40 (the proportion of oxygen in the air is approximately 21%), far exceeding that of conventional flame-retardant fibers (such as flame-retardant polyester with an LOI of about 28-32). It does not melt or drip when exposed to fire, extinguishes itself after removing the fire source, and releases little smoke and no toxic gases during combustion.
· High-Temperature Stability: The long-term usage temperature can reach 200-250℃, and the short-term can withstand 300-400℃ high temperatures (specifically depending on the raw materials and pre-oxidation degree). It still maintains structural integrity and mechanical properties in high-temperature environments.
· Chemical Resistance: It has certain resistance to acids, alkalis, and organic solvents, and is not easily eroded by chemical substances, suitable for use in harsh environments.
· Certain Mechanical Properties: It has certain tensile strength and toughness, and can be made into materials with stable structure through nonwoven fabric processing techniques (such as needle-punching, spunlace).
II. Processing Technology of Pre-Oxygenated Nonwoven Fabrics
Pre-oxygenated fiber needs to be processed into continuous sheet-like materials through nonwoven fabric processing techniques. Common processes include:
· Needle-punching Method: By repeatedly piercing the fiber mesh with the needles of the needle-punch machine, the fibers interlock and strengthen each other, forming an nonwoven fabric with a certain thickness and strength. This process is suitable for producing high-strength, high-density pre-oxygenated fiberless fabrics, which can be used in scenarios requiring structural support (such as fireproof panels, high-temperature filtration materials).
· Spunlaced Method: Utilizing high-pressure water jets to impact the fiber mesh, the fibers interweave and bond together. The spunlaced pre-oxygenated fabric has a softer feel and better breathability, and is suitable for use in the inner layer of protective clothing, flexible fireproof padding, etc.
· Thermal Bonding / Chemical Bonding: By using low-melting-point fibers (such as flame-retardant polyester) or adhesives to assist in reinforcement, the stiffness of pure pre-oxygenated fiberless fabric can be reduced, and the processing performance can be improved (but note that the temperature resistance of the adhesive needs to match the usage environment of the pre-oxygenated fabric).
In actual production, pre-oxidized fibers are often mixed with other fibers (such as aramid, flame-retardant viscose, glass fiber) to balance cost, feel and performance (for example, pure pre-oxidized non-woven fabric is hard, but adding 10-30% flame-retardant viscose can improve its softness).
III. Specific application scenarios of pre-oxidized fiber non-woven fabric
Due to its flame-retardant and high-temperature resistant properties, pre-oxidized fiber non-woven fabric plays a key role in multiple fields:
1. Firefighting and personal protection
· Firefighter's inner lining / outer layer: Pre-oxidized non-woven fabric is flame-retardant, high-temperature resistant and breathable, and can be used as the core layer of firefighting suits to block the transfer of flames and high temperatures, protecting the skin of firefighters; when combined with aramid, it can also improve wear resistance and tear resistance.
· Welding / metallurgical protective equipment: Used for welding mask linings, heat-resistant gloves, metallurgical workers' aprons, etc., to resist sparks flying and high-temperature radiation (with a short-term temperature resistance of over 300°C).
· Emergency escape supplies: Such as fire blankets, escape mask filter materials, which can wrap the body or filter smoke during a fire (low smoke and non-toxicity are particularly important).
2. Industrial high-temperature protection and insulation
· Industrial insulation materials: Used as the inner lining of high-temperature pipes, boiler insulation pads, etc., to reduce heat loss or transfer (long-term resistance to 200°C and above environments).
· Fireproof building materials: As the filling layer of fireproof curtains and firewalls in high-rise buildings, or cable coating materials, to delay the spread of fire (meeting the GB 8624 fire resistance grade B1 and above requirements).
· High-temperature equipment protection: Such as oven curtains, heat insulation covers for kilns and ovens, to prevent personnel from being burned by the high-temperature surface of the equipment.
3. High-temperature filtration fields
· Industrial smoke gas filtration: The temperature of smoke gas from waste incinerators, steel mills, chemical reaction furnaces often reaches 200-300°C, and contains acidic gases. Pre-oxidized non-woven fabric is resistant to high temperatures and corrosion, and can be used as the base material for filter bags or filter cylinders, efficiently filter.
4. Other special scenarios
Aerospace auxiliary materials: used as fireproof insulation layers inside spacecraft cabins and heat insulation gaskets around rocket engines (which need to be reinforced with high-temperature resistant resins).
Electrical insulating materials: Used as insulating gaskets in high-temperature motors and transformers, they can replace traditional asbestos materials (non-carcinogenic and more environmentally friendly).
Iv. Advantages and Development Trends of Pre-Oxidized fiber Nonwoven Fabrics
Advantages: Compared with traditional flame-retardant materials (such as asbestos and glass fiber), pre-oxygenated fiber non-woven fabric is non-carcinogenic and has better flexibility. Compared with high-priced fibers such as aramid, it has a lower cost (about 1/3 to 1/2 of aramid) and is suitable for batch application in medium and high-end flame-retardant scenarios.
Trend: Enhance the compactness and filtration efficiency of non-woven fabrics through fiber refinement (such as fine denier pre-oxygenated filaments, diameter < 10μm); Develop environmentally friendly processing techniques with low formaldehyde and no adhesives; Combined with nanomaterials (such as graphene), it further enhances high-temperature resistance and antibacterial properties.
In conclusion, the application of pre-oxidized fibers in non-woven fabrics hinges on their composite properties of "flame retardancy and high-temperature resistance" to address the performance shortcomings of traditional materials in high-temperature and open flame environments. In the future, with the upgrading of industrial safety and fire protection standards, their application scenarios will be further expanded.
