Crosslinking means the introduction of new covalent CC- bonds into polymer molecules. The material is transformed from a thermoplastic to a duroplastic / thermoelastic state. It will not melt anymore.

For suitable materials, the following improvements can be achieved:

• Increase in modulus and strength
• Resistance against stress cracking corrosion
• Improvement of creep and stress rupture properties
• Improvement of bending stability
• Decrease in ultimate elongation
• Reduction of cold flow
• Increase in hardness
• Improvement of long-time behaviour under inner pressure

Improvement of stability in enhanced temperature:

• Improvement of the dimensional stability under heat influence
• Improvement of hot-set resp. hot-modulus
• Improvement of flame retardancy
• Increase in resistance against thermal pressure
• Increase in resistance against wire heating

Resistance against solvents:

• Improvement in swelling resistance
• Improvement in stress cracking resistance
• Improvement in resistance against solvents, oil and water

Radiation crosslinking is mostly performed with the following materials

• Polyethylene in all its forms and their blends, e.g. low density (LDPE), linear low density (LLDPE), medium density (MDPE) and high density (HDPE)
• Ethylene copolymers (EVA, EPDM, EEA, EBA, EMA, CSM etc)
• Thermoplastic elastomer (TPE)
• Polyvinylchloride (PVC)*
• Polyurethane (PU)*
• Polyester (PBT)*
• Polyamides (PA 6, -66, -11, -12)*
• Polyvinylidenfluoride (PVDF)*
• Copolymer of ethylene/tetrafluoride (ETFE)*
• silicon rubber*

Goods that are mostly crosslinked are:

• Cables and wire insulations or their sheathing
• Tubes, mostly PE- tubes (PEXc- type)
• Polyolefin foams
• Heat shrinkable tubes
• Moulded articles