A variety of methods exist for vulcanization. The economically most important method (vulcanization of tires) uses high pressure and temperature after the curative has been added to the rubber. A typical vulcanization temperature for a street-vehicle tire is 10 minutes at 177 °C. This process employs the technique known as compression molding, where the rubber article is intended to adopt the shape of the mold. Other methods, for instance to make door profiles for cars, use hot-air vulcanization or microwave-heated vulcanization (both continuous processes).
Five types of curing systems are in common use as follows:
- Sulfur systems
- Metallic oxides
- Urethane crosslinkers