High-density polyethylene: Characteristics
What PE100 means for a pipe's 50-year life
What PE100 means for a pipe's 50-year life What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.HDPE grades are chosen by density, melt flow, molecular weight distribution and environmental stress-crack resistance (ESCR). Pipe resins are classified by long-term strength (PE80, PE100). Colour and contamination matter for recycled HDPE: natural (uncoloured) recyclate from milk bottles sells above mixed colours.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Density | about 0.941-0.965 g/cm3 | Higher density gives stiffness and barrier; lower density gives toughness and ESCR. | standard polymer data |
| Minimum required strength (pipe) | PE100: 10 MPa at 50 years, 20°C (ISO 9080 classification) | Determines pipe wall thickness and pressure rating. | ISO 12162 / ISO 4427 (indicative) |
| Melt flow index (190°C) | blow moulding about 0.2-1 g/10 min (2.16 kg); injection 4-30 (indicative) | Sets processing method and part performance. | industry standard (indicative) |
| Environmental stress-crack resistance | measured by ESCR or notch tests (hours to failure) | Critical for detergent bottles, drums and pipes. | industry standard |
| Carbon content | about 86% by mass | About 3.1 t CO2 per t if burnt. | stoichiometric |
Commercial grades
- Blow moulding (chromium-catalysed, bottles, jerricans, drums)
- Injection moulding (crates, caps, pails)
- Film (carry bags, liners)
- PE100 and PE100-RC pipe (water, gas)
- Raffia and monofilament
- UHMWPE (fibres, implants)
- Recycled HDPE (natural and mixed colour)