The mainstream production of nylon BCF adopts an integrated one-step production line of spinning, drawing, and expansion. First, the nylon chips are dried and dehydrated, then melted by a screw, and the molten material is extruded through a metering pump and spinneret to form primary filaments. The filaments are then cooled by side blowing air and lubricated with oil; the filaments enter the hot roller for strength enhancement, and then are sent to the high-temperature expansion chamber, where the hot air flow causes the fibers to form stable three-dimensional curls, completing the expansion and shaping process; finally, they are wound into a tube through network nodes and are collected into a cylinder. The modified types can add flame retardant and anti-stain mother powder at the raw material stage to achieve functional modification. The entire process is controlled by numerical control for temperature and pressure, and compared to the two-step production method, the production efficiency is increased by 30%, with lower energy consumption. It is the main production process used by chemical fiber factories at present.
