LLDPE (Linear Low-Density Polyethylene) is a linear polyethylene copolymerized from ethylene and α-olefins (e.g., butene, hexene, octene). With short, evenly distributed side chains, it combines LDPE's flexibility with HDPE's strength. Falling within the low-density polyethylene range, it is a core material for films, pipes, and injection-molded products. LLDPE density is primarily affected by comonomer type, content, and polymerization process. Virgin material density has a narrow range, with a slight increase after filling modification. Accurate density is critical for film thickness control and pipe pressure-bearing design.

• Virgin LLDPE: 0.915–0.925 g/cm3, typical value 0.920 g/cm3. It offers good flexibility, puncture resistance, and low-temperature resistance with low density, suitable for packaging films, agricultural films, stretch films, and cling films.

• Hexene Copolymer LLDPE: 0.918–0.926 g/cm3. Increasing hexene content slightly raises density, optimizing tear and puncture resistance for heavy-duty packaging and stretch films.

• Octene Copolymer LLDPE: 0.916–0.924 g/cm3. Octene monomer provides superior toughness and stress crack resistance with stable density, suitable for high-end food packaging films and pipes.

• Filled Modified LLDPE: 0.920–0.950 g/cm3. Inorganic fillers like calcium carbonate and talc increase density, reducing costs and improving rigidity for low-end injection-molded products and pipes.