What it is…

Heat shrink tubing is exactly what its name indicates: it is tubing that shrinks when heat is applied. It can be used for a wide range of purposes and can be helpful for doing both preventative maintenance and making repairs.

How to use it…

Heat shrink tubing can be used many different ways. Common preventative maintenance applications include relieving strain, providing additional insulation, and sealing the cable.

When heat shrink tubing is applied to terminals or connectors, it can help relieve physical stress caused by flexing and bending. While flexing and bending can damage insulation and even the cable’s conductor, a layer of heat shrink tubing helps the cable withstand impact, even in cables with built-in strain relief. For more challenging flex applications, requiring firmer strain relief, semi-rigid heat shrink tubing is recommended.

Not only can heat shrink tubing provide additional strain relief, but it can also provide extra insulation. Heat shrink tubing has great electrical qualities which makes it ideal for use with connections, terminations, and circuit board applications requiring additional environmental and electrical protection.

Heat shrink tubing also provides an extra layer of protection for the cable by working as a sealer. It can be placed over substrates, connections, joints, and gaps to protect them from moisture, chemicals, and dust. Tubing defends against environmental hazards by providing UV, oxidation, corrosion, and abrasion resistance as well.

Although heat shrink tubing can be utilized in many preventative maintenance applications, it can also be extremely helpful when making repairs. Whether the fixes are temporary or permanent, heat shrink tubing can be used to cover damaged cable jackets, insulation, connections, or cable splices. It makes for a quick and easy fix while you wait for the cable to be replaced, but it also works effectively enough to serve as a permanent repair in some cases.

When making repairs to the jacket or insulation, be sure to check that the rest of the cable is undamaged. Look to see that the conductor and any insulation between individual conductors are intact to avoid shorts.

Finally, heat shrink tubing can simply be used to make life a little easier. It can bundle and organize cables or just mark circuits for easy cable identification. Heat shrink tubing is available in a wide variety of colors and can be printed with permanent labels, so marking circuits is simple.

How to choose it…

There are several factors to consider when choosing heat shrink tubing. Beyond the usual considerations of temperature and voltage ratings, environmental hazards, and other application requirements involved in choosing cable products, heat shrink tubing requires attention to a few more details.

First are sizing requirements necessary to ensure that the heat shrink will fit snugly in its application and work the most effectively. The sleeve diameter is crucial in heat shrink tubing. The tubing must be large enough in its original state to fit over any large or irregular surfaces, but it must also have a final diameter small enough to ensure that it will shrink to fit tightly around those parts. That is where the shrink ratio comes in.

The shrink ratio indicates how small the tubing will become once heat is applied. These ratios usually range from 6:1 to 2:1. For tubing with a 2:1 ratio, the final product will be half of its original size once it is heated. Tubing with a 6:1 ratio, in its original state, will be six times larger than the final size of the tubing after it is shrunk. These high shrink ratios leave room for irregular parts, allowing the tubing to slide over large objects while shrinking enough for a snug fit over smaller sections. This is important to ensure that the heat shrink provides an adequate fit and an effective seal.

Other considerations are wall thickness and rigidity. Requirements for these depend on the individual application. Stiff tubing with thick walls may be necessary for applications where extreme durability and strain relief are primary concerns. For other applications, thin walled or less rigid tubing may be perfectly adequate.

Another thing to consider when choosing heat shrink is how the tubing will be heated. Consider adding a heat gun to your order. Heat guns are recommended because they provide control over temperature and air flow. However, butane torches may also be used to apply heat. Ideally, heat is applied evenly over the entire surface of the tubing.

The shrink temperature also varies from material to material, so be sure to check that the temperature is realistic for each application.

Though these are all important things to consider when choosing heat shrink tubing, it is a tool well worth the thought. It can be helpful in many situations, from big projects to small details, from important factory repairs to simple circuit marking.

Now that you know more about heat shrink tubing, what it is, how to use it, and how to choose it, go ahead and start looking for the perfect heat shrink tubing solution for your needs.