HDPE (high-density polyethylene)

HDPE is the stiff, chemical-resistant polyethylene of milk bottles, detergent bottles, drums, crates and pipe. Density runs 0.94–0.97 g/cm³. The scrap trade splits it by colour and process: natural (unpigmented — the UK milk bottle stream is the world's reference grade, because natural recyclate can be recoloured into anything), mixed colour bottles, and blow versus injection grade, distinguished by melt flow — blow moulding wants MFI 0.3–0.7 g/10 min, injection 4–8.

Key parameters: MFI, density, ash and colour. Bottle scrap classifies under HS 3915.10; pellets under 3901.20. End uses for rHDPE include pipe and conduit, non-food bottles, crates, and heavy-duty sacks. In this corridor, UK natural bales feed Turkish rHDPE producers, with caps-on tolerance and drained-bottle discipline written into the acceptance spec.