Thermal stress – The heat required to shrink heat shrink tubing can damage delicate fibers. It shrinks radially when heated to form a tight-fitting seal around wires, cables, and mechanical elements. While a range of materials can be used to make heat shrink. Avoid residual bubbles in the protective tube to ensure the temperature characteristics and long-term reliability of the optical fiber connector; 2. Polyolefin heat shrink tubing offers protection against abrasion, moisture, and environmental hazards while. Proper installation is critical to the performance of the heat shrink tube. However, like any other tool.