2020-12-30
Special fibers are chemical fibers with special physical and chemical structures, properties and uses, or special functions. Most of these fibers are used in industry, national defense, medical care, environmental protection and high-end science. Special fibers have different special properties, such as strong corrosion resistance, low wear resistance, high temperature resistance, radiation resistance, flame resistance, high voltage resistance, high strength and high modulus, high elasticity, reverse osmosis, filtration, adsorption, ion exchange, conduction Light, conductivity and various medical functions. Classificationedit Special fibers can be divided into corrosion-resistant fibers, high-temperature-resistant fibers, flame-resistant fibers, high-strength and high-modulus fibers, functional fibers and elastomer fibers according to their performance. ① Corrosion-resistant fiber: fluorine-containing fiber. There are polytetrafluoroethylene fiber (Teflon TFE), tetrafluoroethylene-hexafluoropropylene copolymer fiber (TeflonFEP), polyvinylidene chloride fiber (Kynar), ethylene-chlorotrifluoroethylene copolymer fiber (Halar) and so on. ②High temperature resistant fiber: There are polyisophthalamide metaphenylene diamine fiber (No-mex), polyimide fiber (Αримид ∏Μ), polyphenylsulfonamide fiber (СульФон-Τ), polyamide-imide fiber Fiber (Kermel), polybenzimidazole fiber (PBI), etc. ③Fire-resistant fiber: phenolic fiber (Kynol), aromatic polyamide surface chemical treatment fiber, metal chelating fiber, polyacrylonitrile pre-oxidized fiber (Pyromex), etc. ④High-strength and high-modulus fibers: Polyp-phenylene phthalamide fiber (Kevlar), aromatic polyamide copolymer fiber (HM-50), heterocyclic polyamide fiber (Bниивлон СΒΜ), carbon fiber (Torayca) , Graphite fiber (M40), silicon carbide fiber, etc. ⑤Functional fibers: hollow fiber semi-permeable membranes (B-9, B-10, PRISM, etc.), activated carbon fibers (KF, etc.), superfine fiber felts (Ф∏∏15, etc.), oil-absorbing fiber felts (Tafnel, etc.), Optical fiber (Crofon, Eska, etc.), conductive fiber (Antron Ⅲ), etc. ⑥ Elastomer fibers: There are polyester and polyether polyurethane fibers (Spandex), polyacrylate fibers (Anidex), polybutylene terephthalate fibers (Fibre-L), etc. Preparation processedit Most specialty fibers are made by wet spinning. Some special fiber preparation processes are more difficult, such as spinning linear or low molecular weight fibers with traditional spinning technology, and then performing cyclization, crosslinking, metal chelation, high temperature heat treatment, surface physical and chemical treatment or plasma. Processes such as body treatment can be used to produce finished fibers; others need to adopt emulsion spinning, reaction spinning, liquid crystal spinning, dry jet wet spinning, phase separation spinning, high-pressure electrostatic spinning, high-speed airflow melt jet and special Compound spinning technology and other new spinning processes; some use existing synthetic fibers to obtain various ion exchange groups through functional group reactions or convert them into special fibers. |