When you are looking for shrink tubing with a lower shrink temperature, you should consider using FEP shrink tubing. This tubing works similar to PTFE, but does not require as high a temperature in order to shrink, when it is applied. PTFE requires approximately 654 to 670 degrees Fahrenheit in order to transform and shrink. FEP, on the other hand, only needs in the range of around 420 degrees Fahrenheit of heat to shrink.
Use the Recovered Diameter to Help Select FEP Shrink Tubing
In order to obtain the correct size of FEP shrink tubing, you should determine what the recovered wall size will be after it is shrunk, by working backwards. First, start off by measuring the diameter of the location where the tubing will be applied, and make sure you add a small amount to cover the tubing wall. Now, take this amount to compare the recovered diameters of the tubing and find the one which will be the closest.