PTFE heat shrink tubing protects wires in a range of applications. After being placed around the wire, the tubing melts around the wire to create a protective coating. There are different types of heat shrink tubing. To ensure you buy the right option for your application, you should ask the following questions. 

1. What is the shrink ratio?

The shrink ratio refers to the difference between the original size and the size the tubing shrinks to. You generally want a higher ratio to create a tight seal over irregularly shaped objects. When you're dealing with a uniform wire, in contrast, you may be fine with a smaller ratio. 

A larger ratio gives you more room to insert wires of irregular sizes. Then, when the tubing shrinks, it tightens around the wire. With a smaller ratio, you slip in the wire, and then, the tubing just shrinks a little bit around the wire. 

2. Is the seal moisture-resistant? 

To create a moisture-resistant seal, the tubing heats and bonds to the underlying surface. You need to check if the tubing you buy offers this capability. You also need to ensure that the wire can withstand the bond without breaking down. 

3. What are the maximum temperatures for shrinking and operating?

These tubes shrink under heat. You need to know how much heat you need to apply to produce the shrinking. Then, at the same time, you need to know how much heat the tubing can withstand. This is critical if you're using the tubing in a place with hot temperatures such as around certain machinery. 

4. Does the tubing offer protection from abrasion and chemicals?

People often use heat shrink tubing in stressful environments. The tubing may be exposed to harsh chemicals or it may need to withstand abrasion or rubbing. Think about what the tubing is going to go through in your facility. Then, make sure the tubing you select can stand up in those conditions. 

5. Is the tubing rigid or flexible?

Do you want tubing that cannot move? Do you need tubing that can be flexible and move as needed? Ultimately, this depends on your application. You just need to make sure you select the tubing material that can meet these needs. 

6. Is the tubing UV resistant?

You also have to consider if the tubing is UV resistant. This is particularly important when you use the tubing to cover wires that run outside. 

7. What is the tubing's dielectric strength?

Dielectric strength refers to how much voltage the tubing can handle. You need high dielectric strength if you want to prevent electricity from dissipating from the wire. 

Not sure what else to ask? Then, an industrial supplier that sells heat shrink tubing—such as Tef-Cap Industries. They'll be able to walk you through the questions you need to consider.