LLDPE is a resin used in plastics processing, mainly for film. This page covers what it actually does and how it compares to LDPE and HDPE.
What is it?
LLDPE is polyethylene classified as linear with short-chain branching (ASTM D4976) — structurally distinct from LDPE’s long-chain branching. ASTM D1248 places LLDPE’s density at 0.915–0.935 g/cm³. For film applications specifically, ASTM D4635 groups LLDPE with LDPE under a 0.910–0.925 g/cm³ range for general-use and packaging film.
Why should I use it?
- A structural difference from LDPE that shows up directly in film performance — see Limitations for what that means when choosing between the two.
- A different density/rigidity trade-off compared to HDPE too — see Limitations for that comparison as well.
How it’s used
In Plastics & Polymers, LLDPE is used mainly for film, under the same ASTM D4635 specification that covers LDPE film. Tear resistance for polyethylene film is measured under a standardized method, ASTM D1922. In the US, plastic bag, sack, and wrap waste — predominantly LDPE/LLDPE film — totaled 4.2 million tons generated in 2018, of which only 10% was recycled (EPA).
Limitations — when it isn’t the right choice
- Where higher transparency or easier processing at a lower temperature is the priority over strength, LDPE is the more suitable choice. LLDPE’s short-chain-branched, more linear structure gives it higher tensile strength and better tear resistance than LDPE’s long-chain-branched structure, but LDPE is more transparent and easier to process at lower temperatures. (A dedicated comparison article — HDPE vs. LDPE vs. LLDPE — is planned.)
- Where maximum stiffness is the priority instead of film-grade flexibility, HDPE tends to be the better fit. HDPE’s higher density (0.940–0.970 g/cm³ vs. LLDPE’s 0.915–0.935 g/cm³, per ASTM D1248) generally gives it a rigidity advantage over LLDPE.