Materials
The Material we use is PMMA (POLY METHYL METHAL ACRILATE) one of the best for optical properties and has refractive index 1.33
Properties of PMMA
Approximate Value
| Tensile strength | 55 - 80 MN/m2 |
| Tensile Modulus | 2-3 GN/m2 |
| Elongation at Break | <10 % |
| Flexural Strength | 100 - 150 MN/m2 |
| Notched Impact Strength | < 3 kJ/m2 |
| Specific Heat | 1.25 - 1.7 kJ/kg/°C |
| Glass Transition Temperature | 100 °C |
| Heat Deflection Temperature | <100 °C |
| Coefficient of Thermal Expansion | 5 - 10 x 10-5 / °C |
| Long Term Service Temperature | <100 °C |
| Specific Gravity | 1.0 to 1.2 |
| Mould Shrinkage | 0.001 - 0.005 m/m |
| Water Absorption | 0.1 - 0.5 % (50% rh) |
| Transparency | Transparent |
Properties of Hydrophilic Acrylic
Approximate Value
| Swell Factor | 1.13 at 20°C |
| Water Content | 26% at 20°C |
| Refractive Index @ 20°C hydrated | 1.460 |
| Refractive Index @ 35°C hydrated | 1.457 |
| Refractive Index dry | 1.51 |
| Density | 1.18/cm³ Hydrated |
| Tensile Streangth | 2.5 MPa |
| Elongation to break | 250% |
| Modules | 3.0 MPa |
| UV Blocker | Standard |