mLLDPE EZP2005H — PetroChina Metallocene Polyethylene for Agricultural and Greenhouse Film

Dushanzi Petrochemical Company manufactures EZP2005H at its 600,000-ton-per-year full-density polyethylene complex in Xinjiang Province, one of the largest single-site polyethylene facilities in China. The Unipol gas-phase process uses polymerization-grade ethylene as the primary monomer and hexene-1 as the comonomer, yielding the short-chain branching distribution characteristic of metallocene catalysis. Single-site catalysts produce a narrower molecular weight distribution than conventional Ziegler-Natta resins, which translates directly into more consistent film properties and tighter gauge control on blown film lines.

The resin's MFR of 0.5 ± 0.10 g/10min (2.16 kg load, per GB/T 3682-2000) and density of 0.920 ± 0.002 g/cm³ (GB/T 1033.2-2010) are calibrated for the processing demands of agricultural film converters. At this flow rate, the material extrudes without requiring elevated melt temperatures that could degrade heat stabilizer packages or cause film sticking on the haul-off. The density targets the flexibility window film fabricators need for installations where the film must conform to irregular terrain or stretch across uneven frame structures.

Optical properties are formally specified in the EZP2005H datasheet — a level of commitment not always present in commodity polyethylene grades. Haze is controlled to ≤12% (GB/T 2410-2008), and the gel specification at the 0.8 mm threshold holds to ≤6 fish eyes per 1520 cm² (GB/T 11115-2009). In greenhouse film, optical clarity directly influences light transmission and therefore crop yield. Fish eyes that exceed the 0.8 mm threshold act as initiation sites for tear propagation under wind load; the gel count specification is a durability requirement, not a cosmetic one.

Mechanical properties in the EZP2005H spec set reflect the stresses agricultural film encounters in service. Tensile strength at break reaches ≥20 MPa, yield stress holds at ≥9.0 MPa, and fracture nominal strain reaches ≥350% (all per GB/T 1040.2-2006). Dart drop impact at 25 µm film thickness is specified at ≥200 g (GB/T 9639.1-2008) — a measure of resistance to puncture from hail, debris, and mechanical handling during installation. Films that pass this spec at 25 µm carry a meaningful safety margin when the converter targets 30–40 µm gauge for multi-season applications.

A processing agent is included in the compound. The processing aids reduce melt fracture at die exit and prevent film blocking on the winder — particularly relevant for agricultural film produced in high-speed continuous runs.