Polyethylene knowledge point

Polyethylene is the most important downstream product of ethylene. Polyethylene (PE) accounts for 70% of the world's Polyolefin consumption, accounting for 44% of the total consumption of thermoplastics, and consumes 52% of the world's ethylene production.

Polyethylene can be divided into three categories, namely high pressure low density polyethylene (LDPE), high density polyethylene (HDPE) and linear low density polyethylene (LLDPE). Film is the main processing product, followed by sheet and coating, bottles, cans, barrels and other hollow containers and other kinds of injection and blow molding products, pipes and wires, cables insulation and sheath. It is mainly used in packaging, agriculture, transportation and other departments.

LDPE (high pressure low density polyethylene): non-toxic, tasteless, odorless, translucent spherical or cylindrical particles, excellent resistance to low temperature, chemicals, with good elongation, electrical insulation, but poor humidity, flammable. Density: 0.910 - 0.9408G/CM3 (gram / cubic centimeter), suitable for extrusion, blister, injection molding, vacuum, molding, and transfer molding and other processing methods. The crystallization degree is 55 - 65% and the melting point is 108 - 126.

HDPE (high density polyethylene): non-toxic, tasteless, odorless white powder or columnar or semicircle shaped particles, wear resistance, tolerable, watertightness, flammable, soft. The melting point is about 130, and the relative density is 0.941 - 0.965. It has good heat resistance and cold resistance. It has good chemical stability, high rigidity and toughness, good mechanical strength, dielectric property and good environmental stress cracking resistance.

Density: 0.941 - 0.9708G/CM3 (gram / cubic centimeter), purpose: mainly used for Blister molding, manufacturing a variety of bottles, cans, barrels, industrial storage tanks, hollow packaging.

LLDPE (linear low density polyethylene): odorless, odorless, non-toxic powder or particle, high hardness and anti-wear properties, good heat resistance and good thermal viscosity. Density: 0.91 - 0.940G/CM3 (gram / cubic centimeter); mainly used for making film, also for injection molding, blister. Compared with LDPE, it has the advantages of high strength, good toughness, strong rigidity, heat resistance, cold resistance, and has good environmental stress cracking resistance, tear strength and other properties, and can be acid, alkali, organic solvents, etc..