Polycarbonate vs Soda-lime glass
Polycarbonate and Soda-lime glass are genuine alternatives to one another — a choice somebody actually makes — and differ on 1 measured property, density most clearly.
Polycarbonate vs Soda-lime glass
Polycarbonate
Transparent and almost unbreakable — the safety glazing, the riot shield, the headlamp lens and the spectacle lens.
Soda-lime glass
The commonest glass — silica with soda to lower its melting point and lime to stop it dissolving in water.
| Property | Polycarbonate | Soda-lime glass |
|---|---|---|
| Crystal system Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | amorphous |
| Density | 1.2–1.22 g/cm³ | 2.44–2.55 g/cm³ higher |
| Tensile strength Only one of the two has a figure we can stand behind, so there is nothing to compare. | 55–75 MPa | Not known |
Choosing between them
Polycarbonate is recorded as a substitute for Soda-lime glass — stronger, lighter.
What it gives up: Scratches easily and yellows in ultraviolet unless coated, and the coating is what fails first.
In this application, on the evidence cited above.