What is vulcanisation?
Vulcanisation is a chemical process in which elastomers are vulcanised by cross-linking their Polymer chains into a permanently elastic state. In the process, plastically deformable Raw rubbers Dimensionally stable, elastic and resilient rubber products with defined elasticity, Hardness and consistency.
How does vulcanisation work?
Polymer chains are usually characterised by the addition of Crosslinking chemicals - e.g. Sulphur, Peroxides or Silane compounds - cross-linked at an elevated temperature. This process typically takes place at temperatures between 140°C and 200°C directly in the mould. For complex components in particular, a Autoclavespost-vulcanisation. The mechanical properties can be specifically adjusted by varying the additives and process parameters.
One alternative to vulcanisation using additives is electron beam crosslinking, in which crosslinking is achieved by the targeted application of energy using an electron beam.
Advantages and importance:
- Increase from Tensile strength, tear resistance and elasticity
- Improvement of media, Heat- and Resistance to ageing
- Permanent moulding of Seals, spring elements, composite parts
- Prerequisite for the industrial Series production elastic components
Variants of vulcanisation:
- Sulphur crosslinking - classic with NR, SBR, EPDM
- Peroxide crosslinking - for heat-resistant elastomers (e.g. HNBR, FKM)
- Silane crosslinking - e.g. with Silicones and TPEs
- Metal oxide crosslinking - e.g. with CR
- Electron beam crosslinking - e.g. for TPE