3 Types of Heat Shrink Tubing

3 Types of Heat Shrink Tubing

Creating Stronger Products for Better Results

Heat shrink tubing is an essential component for multiple industries, ranging from aerospace and automotive component manufacturing to battery production and even sporting goods. 

In these industries, the end products being manufactured need to have a specific shape, surface finish, and overall high level of performance in order to withstand the often harsh conditions to which they’re exposed. This is achieved through the use of tooling such as mandrels, inflatable bladders, and SMART Tooling™ — formable, reusable tooling solutions for parts with complex geometries. 

Tooling serves as the ‘mold’ for a composite matrix layup or prepreg — a combination of multiple layers of a reinforcement matrixl like carbon fiber or Kevlar™ along with a specific resin system. Together, these materials are heated and compressed during a curing cycle to form the finished product — an extremely resilient, strong, and long-lasting composite in any number of shapes that’s often lighter than other solutions like steel and other metals. 

But in order to allow the cured product to ‘release’ from the tooling after curing, mandrels and bladders must first be sleeved with heat shrink tubing. This tubing is the ideal alternative to more traditional — and extremely manual — options that include hand-taping of tooling or the use of adhesive release tapes that are fairly common in aerospace and manufacturing industries.

Beyond its use as a release layer, heat shrink tubing can be put to work as a wear-resistant cover for different products and applications. It can also be used as a dielectric protection barrier in applications such as electric vehicle batteries and other power supply applications.  Different materials should be used depending on the application, so let’s explore three specific options — all of which are available at Dunstone — to help you find the right one for your requirements.

3 Solutions for Heat Shrink Tubing

FEP (Fluorinated Ethylene Propylene)

Ideal for use as a release layer, our FEP heat shrink tubing features an extremely controlled shrink process of just 10%. This low shrink percentage and force allows the tubing to properly fit the type of tooling being used without impacting its shape, which is particularly useful when the tooling is inflatable. The tubing begins to shrink at 35ºC (100ºF) and will continue to perform reliably as temperatures increase — even up to 260ºC (500ºF). FEP tubing will also shrink up to 66% faster than competing solutions, reducing the amount of time needed for labor and tooling preparation. Our FEP material is available in larger sizes than many other companies that offer extruded tubing.

Our heat shrink tubing is already one of the thinnest materials available on the market, featuring a wall that’s only 0.002 in. thick versus competing solutions that start at 0.004 in. Our thinner wall design allows the tubing to perform exceptionally well even when placed over an inflatable bladder, reducing the possibility of distortion. With our FEP line, the lower shrink force enables better bladder expansion during cure cycles, which reduces porosity inside composite parts.

Get more insights: Download the FEP product data sheet for additional information.

In addition to our FEP line, Dunstone also offers two additional heat shrink tubing materials that feature higher shrink percentages for use in other applications.

PVC (Polyvinyl Chloride)

Whereas FEP is better suited for production applications as a release layer over tooling, PVC heat shrink tubing increases the shrink percentage possible — allowing it to be used as a wear-resistant covering for packaging or for permanent sleeving requirements. The shrink percentage increases from the 10% possible with FEP to around 70% — allowing the material to be extremely form-fitting without losing any length. It is more cost-effective than other solutions and, along with all Dunstone heat shrink tubing, can be produced for your unique application.

PET (Polyethylene Terephthalate, or Polyester)

PET heat shrink tubing provides the highest-possible shrink percentage of the three options — as much as 75%. Shrinking begins at a higher temperature than our FEP product (typically around 60ºC or 140ºF) and proceeds more slowly. Due to its chemical makeup, PET heat shrink tubing is often used as a protective barrier and for applications in which dielectric protection is needed. Along with our other heat shrink tubing material options, PET tubing is linear-seamed to provide flexibility in sizing.

Enhance Production with Our Customization Capabilities

At Dunstone, we take great pride in customizing our heat shrink tubing products according to our customers’ needs. It all begins by discussing your application and process with our expert team. From there, we will develop a solution designed to eliminate manual processes, reduce waste, eliminate foreign object debris (FOD), increase manufacturing efficiency, and promote stronger post-cure product results. That said, our products are already designed from the beginning to be more advantageous for your production needs.

Diameters and lengths are also extremely customizable. For diameter, sizes are available from 64 mm layflat width up to 320 mm for FEP tubing, and 10 mm lay flat up to 300 mm widths for PVC and PET, ensuring that no matter the size of your tooling, we have a heat shrink tubing solution to accommodate it. 

And when it comes to length, we can produce continuous-length spools up to 2,000 feet or longer. This extended spool length ensures that you not only have all the material you need to stay productive but also benefit from cost savings due to buying more material upfront. The longer spool length also eliminates the need for your team to deal with splicing, as you can simply extract the length of heat shrink tubing needed for your composite parts. And no matter the diameter shrink percentage you’re working with, you can rest assured that the length of the tubing won’t shrink as heat is applied.

Get a Free Sample of Our Heat Shrink Tubing

Whether you’re tired of dealing with hand-taping or are looking to improve quality during the curing process, our heat shrink tubing products are the industry’s best solution for achieving the results you want. Want a free sample of our tubing? Simply let us know what you’re looking to achieve, and we’ll get a sample shipped out to you ASAP.