In recent years, the ignition or combustion of textiles has brought huge losses to people’s lives and property safety, and has become a serious social problem. A lot of research work has been done on flame retardant fibers and their textiles around the world to learn about the research, development and application of flame retardant fibers and their products.
* Classification of flame retardant fibers
Flame retardant fibers mainly include intrinsic flame retardant fibers and modified flame retardant fibers.
Intrinsic flame retardant fibers are mainly inorganic fibers and organic high performance fibers, The inorganic fibers include basalt fiber, glass fiber, quartz fiber, boron fiber, ceramic fiber, etc.; Organic high-performance fibers include aramid, polyimide fiber, polyphenylene sulfide fiber, polysulfonamide and polytetrafluoroethylene fiber.
Modified flame retardant fiber mainly refers to fibers with good flame retardant properties obtained by physical or chemical modification, such as flame retardant polyester, nylon, vinylon and cellulose fibers. The main preparation methods include copolymerized section spinning method, blend spinning method, composite spinning method, and coating method etc..
Due to its unique properties, flame retardant fibers have broad application prospects in civil, military and industrial applications. It can be used not only for flame retardant textiles for automobiles, trains and airplanes, but also for aerospace flame-retardant composite materials, decorative textiles for public places such as hotels, restaurants, hospitals, military, forest fire-fighting protective clothing and home textile products.
* Development status of flame retardant fibers
1.Flame retardant polyester fibers
Flame-retardant polyesters were industrialized as early as the 1980s. In the mid-1990s, phosphorus-based flame retardant monomers developed by Celanese were successfully used in traditional textiles. DuPont, Hearst, Torobo and other companies use organic and inorganic flame retardants and compound flame retardant systems to achieve flame retardant polyester fiber industrialization by copolymerization and blending. Toray Fiber Research Institute (China) Co., Ltd. has obtained cationic dyeable flame retardant polyester fiber by copolymerization and blending. The flame retardant polyester obtained by the BASF company in Germany by copolymerization can be used to produce fibers. Italian Ital Match Chemicals, DSM in the Netherlands and ADEKA in Japan all have patent reports on flame retardant polyester fibers.
In recent years, China’s flame retardant polyester fiber has developed rapidly. Sichuan University, Qingdao University, Beijing Institute of Clothing Technology and Donghua University have research reports or patents for flame retardant polyester fiber. For example, Jiangsu Shenghong Group, Shanghai Petrochemical, Yihua Limited, Shanghai Defulun’s flame retardant polyester filament or short fiber have achieved large-scale production, and achieved export earnings, including the flame retardant polyester industrial yarn produced by Shanghai Petrochemical. The strength reaches 6.0 cN/dtex. However, the performance of the flame retardant polyester fiber against melt drop and smoke suppression still needs to be further improved.
2. Flame retardant polyamide fibers
Research on flame retardant polyamides is mostly concentrated in the field of resins, and is mainly based on blending flame retardant. BASF, Rhodia, DSM and other companies are representative of flame retardant plastic products. However, the flame retardant polyamide fiber is difficult to prepare, and only EMS of Switzerland has announced the development of copolymerized flame retardant polyamide fiber, but there is no commercial product.
China’s research on copolymerized flame-retardant polyamide fibers is mainly concentrated in universities and research institutes, and has not yet been industrialized. Donghua University and Guangdong Xinhui Meida Co., Ltd. have jointly developed flame-retardant polyamide 6 fiber, but the long-lasting water-resistant resistance is limited. Shenma’s B890UN grade and a few other flame retardant polyamide products from other companies are added to phosphorus or other halogen-free flame retardants by mechanical blending, and their flame retardant properties can reach UL94 V-0. Shanghai ANTU Flame Retardant Fiber Co., Ltd. also reported on sheath-core flame retardant polyamide 6 fiber. The bio-based polyamide 56 fiber developed by Shanghai Cathay Industrial Biotech has intrinsic flame retardant properties, a limiting oxygen index of more than 32, and a fiber strength of ≥ 4.5 cN/dtex, which is widely used in the field of flame retardant clothing and decoration. The FR4 CCL produced by Shenzhen Core-Tex Composite Materials Co.,Ltd. has intrinsic flame retardant properties.
3. Flame retardant regenerated cellulose fibers
The research on flame retardant cellulose fiber and its products abroad is ahead of the domestic market and has already achieved industrialization. Companies such as Lenzing in Austria, Kemira in Finland, and Asahi Kasei in Japan have realized the industrialization of flame retardant regenerated cellulose fibers by blending. The fibers have been widely used in protective clothing, knitted fabrics and home textiles.
Domestic Qingdao University, Tianjin Polytechnic University and CHTC Helon Co., Ltd. have independently developed silicon-based, phosphorus-based and phosphorus-nitrogen flame retardants to prepare flame retardant viscose fibers with good performance; Tangshan Sanyou Group Xingda Chemical Fibre Co., Ltd. and Jilin Chemical Fiber Group Co., Ltd. developed phosphorus-based flame retardant viscose fiber using phosphorus-based flame retardant; SOL Flame-Retardant Fiber Co., Ltd. has developed a new generation of environmentally friendly silicon-nitrogen flame retardant viscose fiber. However, the strength and flame retardant durability of the flame retardant viscose fiber are still to be further improved.
4. Flame retardant vinylon
At present, only China, Japan and North Korea have industrialized production of Vinylon, but neither Japan nor North Korea has flame retardant vinylon products.
China’s flame retardant vinylon was developed by Sichuan University in the 1980s in cooperation with Sichuan Vinylon Works, At the beginning of this century, the former General Military Reserve began to organize Sichuan University and Sichuan Vinylon Plant to develop high-strength vinylon, On this basis, the Military Reserve Institute continued to organize Sichuan University and Shanghai Quan Yu Biotechnology Co., Ltd. to independently develop a high-efficiency halogen-free, low-smoke, non-toxic flame retardant that integrates acid source, carbon source and gas source, and developed a complete set of process technology for the production of flame retardant vinylon, successfully produced a high-strength flame-retardant vinylon with limiting oxygen index of 29, fiber strength of ≥ 7.5 cN/dtex, and dyeability. Flame-retardant vinylon and other flame-retardant fiber blended fabrics have been used in the Armed Police Snow Leopard Commando, Falcon Commando, Armed Police Air Combat Brigade, Armed Police Rescue Force, Rocket Army Battle Suit, and PLA Peacekeeping Force.
* Trend of flame retardant fiber development
With the increasing awareness of human safety and the continuous improvement of flame retardant regulations, the development of flame retardant textiles will continue to increase, especially permanent flame retardant textiles will become a new hot spot in the market. The research on flame retardant modified polymer fibers may show the following development trend.
1. Long-lasting environment-friendly high-quality flame retardant fibers
Long-lasting environmental protection and high-quality flame-retardant fiber is the future development trend. Such as the long-acting flame-retardant, anti-melt, anti-smoke integrated melt-spun fiber, high-strength environmentally friendly long-lasting flame-retardant wet-spun fiber. Flame retardant polymer processability, flame retardancy, resistance to droplets, smoke suppression and the balance of mechanical properties are the future research and development direction of flame retardant fiber.
2. Functional composite flame retardant fibers
Flame-retardant, stain repellent, water-repellent, antibacterial and other composite functional fibers are the future development trend.
3. Green and environment-friendly flame retardant fibers
The development of high-efficiency, non-toxic, halogen-free, smoke-free, and droplet-free flame retardant fibers is a future development trend.
4. Comfortable flame retardant fibers
In the case of comfortable flame retardant fibers, it should have both flame retardancy, heat and moisture comfort, and good processability.
5. High-tech flame retardant fibers
High-tech flame-retardant fiber has unique molecular structure, no need to add flame retardant or modification, and it has high temperature and flame retardant performance, and has high added value and good economic benefit. It is the future development direction of flame retardant fibers.