What Is A Heat Shrink Tubing?

The heat shrink tubing, also referred to as heat shrink is a plastic tube that shrinks on heat being applied to it. The heat shrink generally made of nylon or polyolefin shrinks in diameter on heat being applied to it. It is mostly used to insulate wires and to provide resistance to abrasion and other environmental factors that may cause damage to conductors, connectors, joints and terminals used for electrical engineering.  Apart from the preventive maintenance the heat shrink tubing is also used in repairing the worn out or damaged insulation on wires.

How to use the heat shrink?
The heat shrink tubing in the unshrunk state is fitted on one ends of the wires and slid down onto the joint to cover it. The heat shrink is then shrunk by heating it in an oven or a hot air gun so that it gets wrapped tightly around the wire or the joint. There are other methods also for shrinking the tubing namely using a lighter or a soldering iron. However, these methods are not much recommended as there is a danger of the heat shrink material getting damaged if it came in direct contact with the iron or the lighter or the uncontrolled heat from them may cause uneven shrinkage or melting of the heat shrink material.

Material Used
The material used in a heat shrink differs with each and every application. Some of the most common materials used in a clear heat shrink tubing are as follows.

1. Fluoropolymer(PTFE) – It is used in tubes with an operating temperature range between -55 to 175 degree Celsius. The material has a low coefficient of friction and its resistance to punctures and chemicals is very high. A low cost alternate to it is the FEP
2. Fluorinated ethylene propylene (FEP) Teflon – These tubes provide chemical resistance and protection from exterior heat. The material being chemically inert will not burn or support fire. The reason being that Teflon is a fire retardant. Its operating temperature range is 67 to 204 degree celsiuis.
3. PVC – PVC cables regardless of the operational temperatures and other parameters can withstand upto 150 Volts. Their inner diameter sizes generally vary between 0.31 inches to 1.30 inches.
4. Polyolefin – It is one of the most common heat shrink material that is very flexible and can be used for multipurpose insulations. Their operating range of temperature is between -55 to 135 degree Celsius.

Apart from the above mentioned materials there are other materials too that are used in heat shrinks. To name a few would be Viton, Polyvinylidene Fluoride(PVDF), Fluorinated ethylene propylene, Elastometric and others. As stated earlier it is the type of application that determines the material to be used.