A flexible and economical process has been commercialised for heat-shrinkable products which utilizes reactive silane-groups, which will crosslink in a humid environment.
The moisture crosslinkable polyolefins are linked through a
C-Si-O-Si-C moiety, rather than a C-C bond. The crosslinking usually takes place around 80 degrees Celsius.
Moisture crosslinking offers a greater processing latitude, as the fabrication does not have to take place below the peroxide decomposition temperature as required in the peroxide crosslinking process.
Additionally, the extruded tubing in the moisture crosslinkable process can be cooled quickly during the extrusion process, instead of beginning an increasing thermal cycle to decompose the peroxide.