### **The "Pyramid" Competitive Landscape of Flame-Retardant Fibers: An Analysis of 8 Major Material Technologies and Their Commercialization****◇ The Importance of Flame-Retardant Fibers**Flame-retardant fibers, serving as a crucial pillar of the flame-retardant industry, encompass two main categories: natural and chemical fibers. Beyond the widely recognized flame-retardant cellulose fibers, numerous high-performance fibers also excel in the field of flame retardancy.**◇ Aramid 1313 and Its Properties**Aramid 1313 possesses extremely high heat resistance and stability. Renowned for its outstanding flame resistance, thermal stability, and dimensional stability, it has become a star product in the flame-retardant industry. Its Limiting Oxygen Index (LOI) is as high as 28% or more. It can be used continuously at 220°C without aging and remains stable even under brief exposure to 300°C, showing no shrinkage, embrittlement, softening, or melting.**◇ Performance of Polyimide Fiber**Polyimide fiber features a high oxygen index, with an LOI ranging between 35% and 75%, and has low smoke generation, classifying it as a self-extinguishing material. Furthermore, its high thermal decomposition temperature means polyimide fiber only begins to decompose around 500°C.**◇ Applications of Basalt Fiber**Basalt fiber exhibits non-combustibility and high-temperature resistance. As a representative inorganic fiber, it also holds a place in the flame-retardant field. Its characteristics of being non-combustible, heat-resistant, thermally insulating, and high-strength have led to its widespread application in various sectors such as automotive, construction, and sports. China is currently dedicated to the large-scale production of pure natural, high-performance, and low-cost basalt fibers.**◇ Development of Polyphenylene Sulfide (PPS) Fiber**Polyphenylene Sulfide fiber also demonstrates excellent performance, being heat-resistant and dimensionally stable. Its LOI can reach 34%-35%, with a high melting point of 285°C and good dimensional stability. China has successfully developed nano-composite PPS staple fibers with superior high-temperature and corrosion resistance, addressing the oxidation issues of pure PPS fibers under high-temperature and highly corrosive working conditions.**◇ Advantages of Aryl Sulfone Fiber (China's own brand, often referred to as '芳砜纶')**Aryl Sulfone fiber exhibits physical properties superior to aramid at high temperatures. Its unique physical and chemical properties make it highly promising in the flame-retardant field. The broad application of these high-performance fibers will undoubtedly bring new breakthroughs and development to the industry. As a high-temperature resistant fiber independently developed by China, Aryl Sulfone fiber, while slightly lower in tensile strength compared to aramid, shows significant advantages in flame resistance and anti-thermal-oxidative aging. Its LOI is approximately 33%, and after being heated in 300°C hot air for 100 hours, its strength loss is controlled within 5%. This fiber finds wide application in various fields including protective products, electrical insulation materials, and honeycomb structural materials.**◇ Characteristics of Polytetrafluoroethylene (PTFE) Fiber**Polytetrafluoroethylene fiber, a pioneer in high-temperature flame-retardant fibers, is known for its high oxygen index and temperature resistance. With an extremely high LOI of up to 95%, it can be used for extended periods at 250°C. The development goals for PTFE fiber in China focus on the production of corrosion-resistant PTFE filament and staple fibers, aiming to fill domestic production gaps while meeting environmental needs such as filtering PM2.5.**◇ Flame-Retardant Modification of Polyester (PET)**Improving the flame retardancy of polyester through copolymer modification. Polyester, a leader in global polyester industrial filament production, has an annual production capacity in China of about 1.3 million tons, accounting for roughly 60% of the global total. However, its flammable nature limits its application scope, making flame-retardant modification necessary. Currently, China primarily employs the copolymer modification method, successfully synthesizing flame-retardant polyester with phosphorus in the main chain via in-situ polymerization. Its flame-retardant indicators have reached China's National Standard B2 level, with wash resistance exceeding 30 cycles.**◇ Progress in Flame-Retardant Nylon Fibers**Nylon fiber is a flammable material that produces drips when burning without flame-retardant modification. Therefore, the development of flame-retardant nylon is particularly important. The market currently mainly features reinforced flame-retardant nylon and halogen-free flame-retardant nylon, with polyamide-based flame-retardant fibers like flame-retardant PA66 and flame-retardant PA6 being more common. It is worth noting that due to the high cost of high-purity pentanediamine, nylon 56 fiber has not yet achieved industrial-scale production. However, with the advancement of bio-based nylon 56 fiber projects, its industrial production is imminent.