High-density polyethylene is the tough, chemical-resistant workhorse behind pails, crates, caps, bottles, pipe and cutting boards. It is light, needs no drying and stays tough well below freezing.
Typical HDPE properties
| Property | Typical value | US units | Test method |
|---|---|---|---|
| Density | 0.940–0.965 g/cm³ | 0.034–0.035 lb/in³ | ASTM D792 / ISO 1183 |
| Tensile strength | 20–32 MPa | 2,900–4,600 psi | ASTM D638 / ISO 527 |
| Flexural modulus | 0.8–1.5 GPa | 116,000–218,000 psi | ASTM D790 / ISO 178 |
| Notched Izod impact | 20–200 J/m | 0.4–3.7 ft·lb/in | ASTM D256 |
| Heat deflection, 1.8 MPa (264 psi) | 40–55°C | 104–131°F | ASTM D648 / ISO 75 |
| Water absorption, 24 h | 0.005–0.010% | ASTM D570 / ISO 62 | |
| Mold shrinkage | 1.5–3.0% | 0.015–0.030 in/in | ASTM D955 / ISO 294-4 |
Typical ranges for standard grades, dry as molded, from published data sheets. Your grade’s own data sheet and the lot COA are what count. Notched Izod uses 3.2 mm (1/8 in) bars.
Processing and drying
| Processing | Typical |
|---|---|
| Melt temperature | 380–525°F / 193–275°C |
| Mold temperature | 50–125°F / 10–50°C |
| Drying | Not required |
| Target moisture | Not needed |
| Max barrel residence | Not published |
| General | Typical |
|---|---|
| Clarity | Translucent to opaque |
| Chemical resistance | Excellent: acids, bases, most solvents |
Starting points only. See the full processing temperature chart and drying guide for every resin.
What changes these numbers
- Density sets the balance. Higher density means stiffer and stronger, but lower stress-crack resistance.
- Melt index picks the process. Injection grades run high melt index. Blow molding, pipe and sheet grades run low.
- High shrinkage. HDPE shrinks about 1.5–3%, so large flat parts need care to stay flat.
- Stress cracking. Detergents and surfactants can crack stressed parts. Check the ESCR value for containers that hold them.
Common HDPE grades
- Injection grades
- Blow molding grades
- Pipe grades
- Film grades
- HMW-HDPE
- UV-stabilized grades
Common questions
What is the density of HDPE?
About 0.94–0.965 g/cm³ (0.034–0.035 lb/in³).
What is the difference between HDPE and LDPE?
HDPE has fewer side branches, so it packs tighter: it is stiffer, stronger and more heat resistant. LDPE is softer, more flexible and clearer. See HDPE vs. LDPE.
What temperature can HDPE handle?
It deflects at about 40–55°C under the 1.8 MPa load, but unloaded parts handle around 80°C in continuous use.
Need HDPE, or something close?
A polymer chemist reviews every request, then matches your grade or finds a qualified equivalent and prices it.
What to send for an accurate quote
- The grade name, from any supplier, or a data sheet
- Color (natural, black or a custom match)
- Fill type and percentage, if any
- Melt flow, if you know it
- Quantity for this order and what you use in a year
- Ship-to city and state or province