Low-density polyethylene （LDPE）is a synthetic resin using a high-pressure process via free radical polymerization of ethylene and is therefore also called “high-pressure polyethylene”. Since its molecular chain has many long and short branches, LDPE is less crystalline than high-density polyethylene (HDPE) and its density is lower. It features light, flexible, good freezing resistance and impact resistance. LDPE is chemically stable. It has good resistance to acids (except strongly oxidizing acids), alkalis, and salt, and excellent electrical insulation properties. Its vapor penetration rate is low. LDPE has high humidity and good processability. It is suitable for being used in all types of thermoplastic processing processes, such as injection molding, extrusion molding, blow molding, roto molding, coating, foaming, thermoforming, hot-jet welding, and thermal welding.
LDPE is principally used for making films. It is widely used in the production of the agricultural film (mulching film and shed film), packaging film (for use in packing candies, vegetables, and frozen food), blown film for packaging liquid (for use in packaging milk, soy sauce, juice, bean curds, and soy milk), heavy-duty packaging bags, shrinkage packaging film, elastic film, lining film, building use film, general-purpose industrial packaging film, and food bags.
LDPE is also widely used in the production of wire & cable insulation sheaths. Cross-linked LDPE is the main material used in the insulation layer of high-voltage cables.
LDPE is also used in the production of injection-molded products (such as artificial flowers, medical instruments, medicine, and food packaging material) and extrusion-molded tubes, plates, wire & cable coatings, and profiled plastic products. LDPE is also used for making blow-molded hollow products such as containers for holding food, medicine, cosmetics and chemical products, and tanks.
