Description
LDPE (Low-density polyethylene)
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), alkali, salt, excellent electrical
insulation properties. Its vapor penetration rate is low. LDPE has
high fluidity 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.
Applications
LDPE is principally used for making films. It is widely used
in the production of 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 sheath. 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.