Advances in Radiation Cross linking of Polymers

Essentially three cross linking process are used in the polymer related industries. Two types of chemical cross linking, those employing organic peroxides or silanes, respectively are still frequently used for the improvement of polyethylene and other polymer based insulations for wire and cable.However, the advantages of radiation cross linking over the chemical process have brought about its steady growth of about 10 to 15 % annually since the mid-1970s, when high energy and high current electron accelerators became widely available for radiation processing. Moreover; energy consumption for the radiation processing is much lower than that for chemical cross linking process. The dose required for the desirable degree of cross linking is determined by the electron current of the accelerator and by the wire or cable speed; therefore, the process control is quite simple. In recent years various radiation sources e.g., X-rays (soft and hard), gamma (y) and ultraviolet (UV) rays and electron beam (EB) are being used in the curing of various polymers, paints, inks, coatings and adhesives.