HDPE – high-density polyethylene (PE 300 / PE 500)
Light, weldable, chemical-resistant polyolefin for sheets, tanks and boards
High-density polyethylene is light and tough, does not absorb water and resists acids, bases and salt solutions. It is weldable, so it is the basis for tanks, vats and ducts, and it is widely used for cutting boards and parts with low mechanical demands. It is not recommended for heavy wear (use UHMW) or above 80 °C.
Designations and equivalents
| System | Designation |
|---|---|
| Abbreviation (ISO 1043) | HDPE (PE-HD, PE 300) |
| Trade names | Polystone G (Roechling, PE-HD 300); TECAFINE HDPE (Ensinger) |
Standards by product form
| Form | Standard |
|---|---|
| Sheets and rods (PE-HD and PE-UHMW) | ISO 15527* |
| Food contact | FDA 21 CFR 177.1520 (depending on grade) |
| Machined part to drawing | ISO 2768 tolerance or as per drawing |
Composition and filler
Pure polymer
| Component | Content |
|---|---|
| HDPE | 100% |
Mechanical properties
Typical values from the stock-shape manufacturer's catalog, 23 °C; ISO/ASTM methods as per the source
| Property | Value |
|---|---|
| Tensile strength | 25 MPa |
| Modulus of elasticity (tensile) | 1,000 MPa |
| Elongation at break | >50% |
| Hardness | Shore D 62 |
| Notched impact | 20 kJ/m² |
Typical physical and thermal properties
| Property | Value |
|---|---|
| Density | 0.95 g/cm³ |
| Maximum continuous service temperature | 80 °C |
| Maximum short-term temperature | 100 °C |
| Minimum service temperature | -50 °C |
| Melting point or glass transition | 131 °C |
| Linear thermal expansion | 150-230 µm/m·K |
| Thermal conductivity | 0.4 W/m·K |
| Water absorption (24 h) | <0.01% |
| Dielectric strength | >40 kV/mm |
| Flammability (UL 94) | HB |
Calculate the weight of HDPE – high-density polyethylene (PE 300 / PE 500) bar, plate or pipe →
Chemical resistance
| Medium | Resistance |
|---|---|
| Acids | Excellent (except strong oxidizers) |
| Bases (alkalis) | Excellent |
| Solvents | Good at room temperature |
| Hydrocarbons and oils | Limited (aromatics and chlorinated solvents cause swelling) |
| Steam and hot water | No (temperature) |
Stock forms and sizes
- Sheet (plate)
- Rod (round bar)
- Weldable sheet
- Profiles
- Raw material: rod (round bar), sheet (plate) and tube, cut to size
- Machined part to drawing or sample, in the same order as the metal parts
- Lot certificate of conformity; FDA/EU 10/2011 declaration when the grade allows
Service temperature, machining and assembly
| Item | Usual practice |
|---|---|
| Service temperature | Continuous service up to 80 °C, short peaks up to 100 °C; minimum -50 °C (unloaded; under load, limited by HDT and creep). |
| Annealing (stress relief) | Not usual. |
| Bonding and welding | Welds very well by hot plate, extrusion and hot air welding. |
| Machining | Machines easily; allow clearance for thermal expansion. |
Typical applications
- Welded tanks, vats and reservoirs
- Cutting boards
- Linings and chutes
- Low-load parts in chemical or wet environments
Alternatives: UHMW for wear; PP for somewhat higher temperature and stiffness.
Frequently asked questions
Which standards cover HDPE?
Sheets and rods (PE-HD and PE-UHMW): ISO 15527*. Food contact: FDA 21 CFR 177.1520 (depending on grade). Machined part to drawing: ISO 2768 tolerance or as per drawing.
Up to what temperature can HDPE be used?
Continuous service up to 80 °C, short peaks up to 100 °C; minimum -50 °C (unloaded; under load, limited by HDT and creep).
Which materials can replace HDPE?
UHMW for wear; PP for somewhat higher temperature and stiffness.
Is HDPE suitable for chain guides?
For light loads, yes; on conveyors with wear, use UHMW, which lasts several times longer.
