Types of Woven Luggage Bags

Overseas production primarily uses polyethylene (PE), while domestic production mainly uses polypropylene (PP), a thermoplastic resin obtained by polymerizing ethylene. Industrially, it also includes copolymers of ethylene with small amounts of α-olefins. Polyethylene is odorless, non-toxic, and has a waxy feel. It possesses excellent low-temperature resistance (minimum operating temperature can reach -70 to -100℃), good chemical stability, and resistance to most acids and alkalis (except oxidizing acids). It is insoluble in common solvents at room temperature, has low water absorption, and excellent electrical insulation properties; however, polyethylene is very sensitive to environmental stress (chemical and mechanical effects) and has poor heat aging resistance.

 

The properties of polyethylene vary depending on the variety, mainly determined by its molecular structure and density. Different production methods yield products with different densities (0.91–0.96 g/cm³). Polyethylene can be processed using general thermoplastic molding methods (see Plastics Processing). Its applications are very wide, mainly used to manufacture films, containers, pipes, monofilaments, wires and cables, daily necessities, etc., and it can also be used as a high-frequency insulating material for televisions, radar, etc. With the development of the petrochemical industry, polyethylene production has grown rapidly, accounting for approximately one-quarter of total plastic production. In 1983, the world's total polyethylene production capacity was 24.65 Mt, with an additional 3.16 Mt under construction.

 

Polypropylene (PP) is a thermoplastic resin produced by polymerizing propylene. It exists in three configurations: isotactic, atactic, and syndiotactic, with isotactic being the main component in industrial products. Polypropylene also includes copolymers of propylene and small amounts of ethylene. It is usually a translucent, colorless solid, odorless and non-toxic. Due to its regular structure and high crystallinity, it has a high melting point of 167℃, making it heat-resistant and allowing for steam sterilization of products-a significant advantage. With a density of 0.90 g/cm³, it is the lightest general-purpose plastic. It is corrosion-resistant, has a tensile strength of 30 MPa, and its strength, rigidity, and transparency are better than polyethylene. Its disadvantages include poor low-temperature impact resistance and a tendency to age, but these can be overcome through modification and the addition of antioxidants.