Spectroscopic approach to determine shrink temperature and duration for heat shrinkable components

Heat shrinkable type is one among the other jointing systems which is used to maintain the continuity of cable especially for long length of cable requirements. In this type, the component shrinks/recovers to its original size (unilateral direction) when heated in an unconstrained state. The technology of low shrink temperature allows the tubing to shrink rapidly thereby minimizing heat exposure. The temperature initially used for expansion/stretch has a significant bearing on the shrink temperature. The heat shrinkable component might shrink differently for different shrink temperatures and duration selected in the shrinking process. Since failure of heat shrinkable component in service can lead to serious consequences, it is desirable to know the effect of improper shrink temperature on the components. The paper discusses the effect of improper selection of, temperature and its duration of application, in the shrink process for stress control, insulating and anti track tubing samples. The study, at microscopic level indicated that improper supply of heat and duration results in incomplete recovery of the component. Also there is formation of internal defects viz., micro voids, clevages, surface delaminations, formation of weak links and poor interfaces between conductor and heat shrinkable component.