Polypropylene (PP) is a thermoplastic plastic formed by the coordination polymerization of propylene monomers. It can be regarded as the “lightweight and fatigue-resistant champion among general-purpose plastics” - due to its regular molecular chain structure and high crystallinity, it has an extremely low density (0.90-0.91 g/cm³), excellent heat resistance (able to be used for a long time at temperatures above 100°C), outstanding bending fatigue resistance (for book hinges), resistance to most acid and alkali solvents, and good electrical insulation. It is widely used in food packaging (meal boxes, yogurt cups), car bumpers, home appliance shells, non-woven fabrics (face masks, diapers), fibers (carpet, ropes), and reusable daily necessities in situations that require light weight, fatigue resistance, and hygiene and safety.