1, the density is different. LDPE density of 0.91g/cm3-0.93g/cm3, is the lightest varieties of polyethylene resin; LLDPE density of 0.918 ~ 0.935g/cm3; HDPE density of 0.941 ~ 0.960g/cm3, is the highest density of the three.
2, the melting point is different, the melting point of LDPE 110 ~ 115 ℃, processing temperature of 150 ~ 210 ℃, if the inert gas, the temperature can reach 300 ℃ is still stable. But the melt and oxygen contact is easy to degrade; LLDPE melting point of 110 ~ 125; HDPE melting point of 130.
3, different uses.
LDPE applications:For seasonings, pastries, sugar, candied fruit, cookies, milk powder, tea, fish and meat floss and other food packaging. Tablets, powders and other pharmaceutical packaging, shirts, clothing, knitted cotton products and chemical fiber products and other fiber products packaging. Laundry detergent, detergent, cosmetics and other daily necessities packaging. Due to the poor mechanical properties of single-layer PE film, so it is usually used as the inner layer of composite bags, that is, multi-layer composite film heat sealable substrate.
LLDPE has penetrated most of the traditional markets for polyethylene, including film, molding, pipe and wire and cable. Leak-proof geomembranes are a newly developed LLDPE market. Mulch, a large extruded sheet, is used as a landfill and waste pond liner to prevent leakage or contamination of the surrounding area.
HDPE is used in extruded packaging film, ropes, woven bags, fishing nets, water pipes; injection molded low-grade household goods and shells, non-load-bearing components, plastic boxes, crates; extruded blow molded containers, hollow products, bottles.
Baidu Encyclopedia_Low Density Polyethylene
Baidu Encyclopedia_Linear Low Density Polyethylene
Baidu Encyclopedia_High Density Polyethylene