The production process of polypropylene fiber is simple, with "one-step spinning" and "two-step spinning". Fibers are produced by polymerization of propylene as raw material, modification of the raw material, melt spinning, melt filtration, blow cooling, winding, and production. Compared with the production process of two-step spinning, one-step spinning has the characteristics of less land occupation, fewer personnel, and lower cost. The problem is that the strength of polypropylene fibers produced by one-step spinning is relatively low. Therefore, the modification of its raw materials is very important. 

Currently, the manufacturing method of polypropylene strong filament is commonly used, which is characterized by using polypropylene resin with a melt flow index of MFI=5-40 and a molecular weight distribution index of MWD<7. It is spun at a speed of 400-1600/min and then subjected to two-stage traction and twisting in a spindle type traction and twisting machine to produce high-strength polypropylene filament with a composite fiber size of 400-1600 min.