LDPE (Low-Density Polyethylene) is produced via high-pressure free radical polymerization, featuring highly branched molecular chains and low crystallinity. It offers excellent flexibility, transparency, and processability, with the lowest density among polyethylenes. It is a traditional core material for films, hoses, coatings, and soft injection-molded products. LDPE density is primarily affected by polymerization pressure and branching degree. Virgin material density has an extremely narrow range, with a slight increase after filling modification. Accurate density is fundamental for soft product design and processing.

• Virgin LDPE: 0.910–0.915 g/cm³, typical value 0.912 g/cm³. It offers good transparency, flexibility, and processability with very low density, suitable for food packaging films, shopping bags, hoses, and coatings.

• High-Flow LDPE: 0.912–0.917 g/cm³. Reduced molecular weight improves flowability with slightly higher density, suitable for thin-walled injection-molded products and precision coatings.

• Toughened Modified LDPE: 0.908–0.914 g/cm³. Elastomer modification slightly reduces density, enhancing low-temperature toughness for frozen food packaging and cold-resistant hoses.

• Filled Modified LDPE: 0.915–0.940 g/cm³. Inorganic fillers increase density, reducing costs and improving stiffness for low-end packaging films and injection-molded miscellaneous parts.