Linear Low Density Polyethylene Film (LLDPE) Properties

Even though the densities of LDPE and LLDPE (0.921 – 0.926 g/cc) are similar, LLDPE displays better tear and impact film properties than LDPEVery flexible, natural milky color, translucent with high impact strength. Excellent for mild and strong buffers, good chemical resistance. Good water vapor and alcohol barrier properties. Poor gas barrier, sterilizable with EtO (EtO stands for Ethylene Oxide, a toxic, cancer causing gas, which is used to sterilize most of plastics) or gamma radiation. Good stress crack and impact resistance.

Blends of branched (LDPE) and linear (LLDPE) low density polyethylene blends are normally used in plastic film manufacturing. This is done in order to achieve advantageous properties inherent to the combination of both resins, such as improved mechanical properties of LLDPE and good processability of LDPE. These blends could be classified into two categories or domains: LLDPE-richer blends and LDPE-richer blends. Blend composition ratio can shift towards each one of the domains depending on the availability of each resin in the market, the processing equipment, and the consumption habits of local market. As an example, the European market mainly produces LDPE-rich blends, while in North America dominates the use of LLDPE-rich blends.

A sustained LLDPE increase in blends has improved some attributes such as:

• Higher mechanical properties.
• Better appearance (transparency, gloss, lower gel level).
• Improved sealing properties.
• Lower production and transformation costs.

The benefits introduced by LLDPE have shifted market to use LLDPE-richer blends in applications such as: high performance bags, cushioning films, tire separator films, industrial liners, elastic films, ice bags, bags for supplemental packaging and garbage bags.