| Feature | Polycarbonate (PC) | Glass Reinforced Polyester (GRP/SMC) |
|---|---|---|
| Chemical resistence | Generally weak resistence against industrial and households chemicals as well as hot steam | Higher resistence against industrial and households chemicals (see table below for details) |
| Outdoor application | Loss of strength because of embrittlement in 2 years | Hardly measurable loss of strength in 20 years |
| Susceptibility to strain of corrosion | High (at the screws and cover fixing points) |
Low |
| Resistance to Ammonia | Not resistant to the ammonia produced by some standard mains cable insulation | Not affected by ammonia |
| Characteristic | Mainly amorphous, eventually minerally filled, shock-resistant plastics with little absorption of water. Unsuitable for long-term dynamic load. | Not melting or thermic deforming stiff plastic. Decomposition from ca. 400°C - short-term temperature loading > 200° possible. No creepage or shrinkage |
| Reinforcement | No reinforcement | 20 - 25% glass fibre |
| Price stability | PC price dependant on oil price | SMC price independent from oil price |
| Classification | Amorph Thermoplast | Duroplast |
| Chemical basis | Polycondensate from Bisphenol A | Compound from UP-resin, glass fibre and non-organic filling materials |
| Melting point | ca. 220° C | Does not melt |
| Refractory deformation temperature | ca. 145° C | Does not deform |
| Permanent temperature resistance (+) | ca. 125° C | > 150°C |
| Permanent temperature resistance (-) | Brittle | -40°C (keeps the good features) |
| Coefficient of thermal expansion | 0.7ˆ10-0.4 | 10ˆ10-6 (like steel) |
| Elasticity E-Modul | ca. 2400 MPa | ca. 9000 MPa |
| Tensile strength | ca. 60 MPa | ca. 55 MPa |
| Bending strength | ca. 70 MPa | ca. 150 MPa |
| Impact strength at RT | Any break (unfilled) | ca. 60 kJ |
| Impact strength at -30°C | Any break (unfilled) | ca. 65 kJ |
| Current leakage strength | CTI 150 | CTI 600 |
| Glow wire test (1.5mm) | Adjustable till 850°C | Adjustable till 850°C |