Polypropylene

Polypropylene is a thermoplastic polymer formed by the polymerization of propylene (a hydrocarbon). These granules are melted through extrusion, pressed through a sheet, and formed into filaments.

With multifilament, the mass is essentially forced through a fine showerhead, resulting in fine threads. With split film, a film is extruded. This film is then split or cut into strips, stretched, heated, fibrillated, and so on, resulting in a net structure.

The fibers are then processed into twisted or braided rope.