High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called “alkathene” or “polythene” when used for HDPE pipes.
With a high strength-to-density ratio, HDPE is used in the production of plastic bottles, corrosion-resistant piping, geomembranes and plastic lumber. HDPE is commonly recycled.
Polyethylene is classified by its density and branching. Its mechanical properties depend significantly on variables such as the extent and type of branching, the crystal structure, and the molecular weight.
There are several types of polyethylene:
- High-Density Polyethylene (HDPE):
- HDPE is known for its large strength-to-density ratio. The density of HDPE can range from 0.93 to 0.97 g/cm³.
- It is classified in five grades: Film, Injection, Blow, Extrusion, Roto.
- Low-Density Polyethylene (LDPE):
- LDPE is defined by a density range of 0.910–0.940 g/cm³ and has more branching than HDPE.
- Linear Low-Density Polyethylene (LLDPE):
- LLDPE differs structurally from conventional LDPE because of the absence of long chain branching.
| Grade | MFI (g/10 min) @ 190°C/2.16 Kg | Density (g/cm³) |
|---|---|---|
| HCH 5110 A | 10 (190°C/21.6 Kg) | 0.951 |
| F7000 | 0.04 | 0.954 |
| MCH 3713 | 0.1 | 0.937 |
| EX5 | 0.28 | 0.949 |
| 0035 | 0.35 | 0.953-0.959 |
| BL3 | 1.2 (190°C/5 Kg) | 0.954 |
| BL4 | 0.35 (190°C/5 Kg) | 0.951 |
| l4 | 11 (190°C/5 Kg) | 0.954 |
| HD5030SA | 3.2 | 0.950 |
| 6040UA | 3.7 | 0.96 |
| H30500 | 4-6 | 0.963-0.967 |
| 52505UV | 5 | 0.952 |
| 220GJ | 5.2 | 0.953 |
| 60505UV | 5.5 | 0.957 |
| HD 62107 | 7 | 0.962 |
| I3 | 8 | 0.962 |
| HD52511 | 11 | 0.952 |
| HD40511 | 11 | 0.96 |
| HD 5218 EA | 18 | 0.952 |
| HD52518 | 18 | 0.952 |
| HD 5620 EA | 20 | 0.958 |
| HD 6070 UA | 7 (190°C/5 Kg) | 0.958 |
| EX3-80S | 4 | 0.954 |
| EX3-100S | 6.2 | 0.948 |
| CRP 100 Black | 0.22 (190°C/5 Kg) | 0.957 |
| CRP 100 N | 0.22 (190°C/5 Kg) | 0.948 |
| 2340UA | 4 | 0.938 |
