LLDPE Resins

Structural features

Linear low density polyethylene (LLDPE Resins) are known as third-generation polyethylene. In addition to the properties of general polyolefin resins, their tensile strength, tear strength, resistance to environmental stress cracking, resistance to low temperatures, resistance to heat, and resistance to puncture are particularly superior.

Although LLDPE belongs to the same density range as LDPE in the past, their basic physical properties and molding and processing characteristics are different because of the different molecular structures and different melt rheology behaviors between them.

Structurally, LLDPE Resins differs from HDPE only in the number of short branched chains; HDPE has a lower number of short branched chains, which ultimately depends on its use.The densities of both LLDPE and LDPE are in the range of 0.91 to 0.925 g/cm3. This higher degree of crystallinity also increases the melting point of LLDPE by 10 to 15 percent compared to LDPE. Higher tensile strength, resistance to penetration, tear resistance, and increased elongation are characteristics of LLDPE that make it particularly suitable for film production. Even impact and tear resistance can be greatly improved if hexene or octene is used instead of butene as the copolymerization monomer. Hexene and octene resin longer side chain in the chain between the role as a "knot" molecules, improving the toughness of the compound. The production of resins using cyclic olefin metal derivative catalysts will have unique properties. These are similar to LLDPE produced with Ziegler catalysts.

LLDPE has similar drawbacks to LDPE with respect to the property of transparency: the turbidity and gloss of LLDPE films are poor, mainly due to the roughness of the film surface caused by its higher crystallinity.The transparency of LLDPE resins can be improved by blending them with small amounts of LDPE.

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