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LLDPE Specific Gravity (Density)

2026-02-05 10:42:48 Injection Molds

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.

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  • 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.

Density parameters are the core basis for film manufacturing, pipe extrusion, and injection-molded daily necessities design. Its low density suits lightweight films and flexible products, and a stable density range ensures uniform film thickness and pipe pressure stability. Density calculations directly influence blown film and extrusion process parameters, while supporting its core properties of flexibility, impact resistance, and chemical resistance.

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