Heat shrinkable tubes are used for a variety of purposes. The most common uses are in the field of electrical engineering, where heat shrinkable tube is used to protect conductors, connections, joints and terminals from wear and tear, and weather damage.
Heat shrinkable tube can be used to repair damaged wires, bundle groups of wires together, and to act as a seal at cable entry points.
Some people use heat shrink tubing to form makeshift aglets for shoelaces, or to bond the ends of other clothing ties.
Heat shrinkable tubes come in several different materials, and each material is designed for a different purpose. Clear heat shrinkable tubes, for example, are designed to be used on areas where the cable or component being protected has markings which need to be read.
Heat shrinkable tubing is also available in colours which match the most common electrical wiring colours.
Some heat shrinkable tubes have adhesive on the inside, which bonds the tubing to the wires or components that it is protecting.
Other heat shrinkable tubing has been designed to have a specific property – such as a low friction coefficient, a high resistance to chemicals, or the ability to continuously operate at extreme temperatures.
The hobbyist electrician will not need such specialist properties. For the hobbyist, standard polyolefin tubing will be fine. The more specialist fluoropolymers are designed for use in the aerospace, military, and train industries.
PTFE is one of the most hardwearing fluoropolymers, but it is expensive, and has a very high shrinking temperature. Fluorinated ethylene propylene (FEP) is a low cost alternative to PTFE. FEP is a good insulator and has good chemical resistance. FEP is slightly less tolerant of extreme temperatures than PTFE, however it is still suitable for most applications.
The best heat shrinkable tube to use in cold environments is neoprene, because this material is highly flexible even at low temperatures. Neoprene has a moderate shrink temperature, and typically has a shrink ratio of 2:1.
Luminous and UV reactive heat shrink tubing is available. These forms of tubing are mainly used where appearance is important, and are popular with the “modding” community – for example computer enthusiasts who make unusually shaped computer cases, and may want to use UV reactive heat shrink tubes to protect wires close to any sharp edges within the case.
Heat shrink tubing is manufactured by several companies, including Tyco, 3M, and Sumitomo.