Vulcanization is a manufacturing process for plastic components with elastic properties. Natural or synthetic rubbers are used as input. If they are initially regarded as thermoplastics, they become elastomers through vulcanization.
This transition is caused by the creation of additional cross-links between the macromolecules of the material.
Instead of a permanent change in shape as a reaction to an external force, these cross-links allow an elastic restoring moment to occur. Vulcanization turns caoutchouc into rubber.
#1 Definition of vulcanization
During vulcanization, cross-links are formed between the macromolecules of polymers under pressure and heat.
The aim is to give the material elastic properties. Cross-linking agents contribute to the formation of the chemical bonds.
#2 Importance of vulcanization
Vulcanization is what makes the production of elastic sealing elements possible in the first place.
It is used as a central step in all common manufacturing processes for O-rings and molded seals:
- Impact vulcanization
- Compression molding
- Injection molding
The degree of vulcanization depends on the parameters of temperature and time. It describes how strong the molecular cross-linking and thus the elasticity is.