Fundamentals and applications of radiation curing

When irradiating insulating material on electrical conductors one has to take into account the radiation-induced hydrogen and the pressure thus built up which may lead to local detachment of the insulating material from the wire. Heat together with the hydrogen may form bubbles in the insulation. Irradiation to induce cross-linking is made with partially crystalline PE. Extrusion, cooling conditions and wire pre-heating in extrusion facilities require special attention, as the mechanical values such shrinking and firm adhesion are determined by these factors. The paper describes the principles, devices, radiation doses applied, and the materials used. (DG)