Radiation curing

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RADIATION CURING:


Radiation curing means that the rubber material is subjected to high energy radiator such as gamma radiation from cobalt 60 or high energy electron radiation. When the radiation penetrate the rubber free radicals  are formed roughly in the same way as with peroxide curing.
The required radiation dose varies for different rubber types from approx.0.05MGy to 0.5 MGy.

GY - gray the SI unit of absorbed dose.one gray in the absorption of one Joule radiation energy by one kilogram of matter.

Cross linking is carried out when the radicals formed by the radiation are combined to give carbon.  Carbon bonds between the molecules.The cross linking bis carried out at lower temperature than conventional curing.

Certain rubber such as silicone rubber, CR rubber, Nitrile rubber and flurocarbon rubber require a relatively small dose in order to be cross linked, while normal types of rubber require considerably higher dose

 With the addition of certain types of activators, so called sensitizers, the radiation doses can be lowered considerably. 0.05 MGy is often quoted as the highest radiation dose for economical radiation curing

 Radiation curing has not yet had any real practical importance in rubber curing, but certain cable, mouldings, hoses, seals, O-rings and gaskets etc. for very special purposes are cross linked by means of radiation
Gamma Irradiation Systems

Gamma ray emitter units are available which can be located between a UHF system and a hot air oven. It may be necessary to adapt the rubber compound for use with this system

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