Polycarbonate is the clear, tough resin used for lenses, light covers, guards, housings and medical parts. It pairs glass-like clarity with notched impact many times higher than acrylic, and heat deflection around 130°C.
Typical Polycarbonate properties
| Property | Typical value | US units | Test method |
|---|---|---|---|
| Density | ~1.20 g/cm³ | ~0.043 lb/in³ | ASTM D792 / ISO 1183 |
| Tensile strength | 60–70 MPa | 8,700–10,200 psi | ASTM D638 / ISO 527 |
| Flexural modulus | 2.2–2.5 GPa | 319,000–363,000 psi | ASTM D790 / ISO 178 |
| Notched Izod impact | 600–900 J/m | 11.2–16.9 ft·lb/in | ASTM D256 |
| Heat deflection, 1.8 MPa (264 psi) | 124–132°C | 255–270°F | ASTM D648 / ISO 75 |
| Water absorption, 24 h | 0.12–0.15% | ASTM D570 / ISO 62 | |
| Mold shrinkage | 0.5–0.8% | 0.005–0.007 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 | 536–653°F / 280–345°C |
| Mold temperature | 158–248°F / 70–120°C |
| Drying | 248–250°F / 120–121°C, 2–4 h |
| Target moisture | ≤0.02% |
| Max barrel residence | 4–8 min |
| General | Typical |
|---|---|
| Clarity | Clear |
| Chemical resistance | Fair: many solvents and bases attack it; stress-cracks |
Starting points only. See the full processing temperature chart and drying guide for every resin.
What changes these numbers
- Thickness and notches. The very high impact numbers come from standard 3.2 mm bars. Thick sections and sharp corners can make PC break in a brittle way.
- Stress cracking. Many solvents, some oils and cleaners, and amines crack stressed PC parts. Check chemical contact before you specify it.
- Melt flow trade-off. High-flow grades fill thin walls but give up some toughness.
- Drying is critical. Wet PC breaks down in the barrel. Dry to 0.02% or less, 0.01% for optical parts.
Common Polycarbonate grades
- General-purpose grades by melt flow
- Optical grades
- UV-stabilized grades
- Flame-retardant grades
- Glass-filled, 10% to 30%
- Medical grades
- PC blends such as PC/ABS
Common questions
What is the heat deflection temperature of polycarbonate?
Typically about 124–132°C (255–270°F) at 1.8 MPa.
Is polycarbonate stronger than acrylic?
Far tougher: notched Izod is about 600–900 J/m vs. 15–25 J/m for acrylic. Acrylic is stiffer, more scratch resistant and has better optics and weathering. See PC vs. acrylic.
How do you dry polycarbonate?
About 120°C (248–250°F) for 2–4 hours, to 0.02% moisture or less.
Need Polycarbonate, 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