Fiber engineering can be based on the chemical modification of spinning materials or the modification of spinning and fiber post-processing technology; Or both chemical modification and physical modification. The obvious examples of chemical modification are the improvement of the stability of polypropylene fiber nylon ties to thermal and photodegradation, body coloring and the development of dyeable polypropylene fibers. Other chemical modifications, including antistatic property, flame resistance, bacteriostasis, light resistance, wear resistance, antifouling property, as well as the improvement of fiber friction and other properties, are also very important.