What types of heat shrink tubing are there and what should I take into consideration when buying it.?

Question

Thinking of getting into RC control cars.

Answer 1

Here is an article I wrote that is very much on topic with your question:

If you thought you could simply walk into the neighboring hardware store and pickup the first heat shrink tubing material that you see on the shelves, think again. Starting with the different types of materials that are available for tubing, much science and logic are involved in identifying and using the right tubing material for your home and office wires and cords. The “overcoat” for wires has different dimensions in expanded and contracted states of the material, comes in different colors and sizes, respond to various temperatures, and perform diverse functions. If you are convinced that buying heat shrink tubing material is not an easy task let alone the actual process of heat shrink tubing, then you are with us through this article.

Let us start with what heat shrink tubing does. As the name indicates, heat shrink tubing uses the ability of the tubing material to respond to heat and bind around the object. For instance, in order to cover, insulate, protect, and label the wires around the office and home, you should wrap the flexible tubing material around the wires and heat the material. A special heat-shrinking gun or an ignition torch can be used as the source of heat. At the right temperature, the flexible tubing material begins to contract on the body of the wires and settles down to fit like an overcoat.

The remainder of this article identifies the different applications of the heat shrink tubing and the type of tubing materials that are suitable for a specific application.

Advanced medical devices and high temperature industrial equipment require high quality tubing materials with least friction and a broad working temperature range. PTFE, a fluoropolymer resin that is a part of Teflon, is the first choice for many advanced industrial applications due to the unique properties of the polymer such as strength and durability. PTFE is used extensively in the chemical and analytical sciences industries. In fact all the three Teflon polymers, PTFE, FEP, and PFA, share common properties like lubricity, chemical resistance, and resistance to high temperature.

While FEP and PFA find similar applications as PTFE, they exhibit some variations in their properties. In addition to high UV transmission ratings, FEP allows gas and vapor to more readily permeate through the material and is more transparent compared to PTFE.

Because FEP had a lower continuous service temperature than PTFE, PFA was developed to overcome the limitation. PFA can be processed for a longer time and has a better texture than PTFE and FEP. As a result it extends the basic application capabilities of PTFE and FEP. Because these resins require very high temperature to shrink, using a controlled temperature oven, their application is limited to industrial and laboratory use. Using a heat gun or an ignition torch can result in uneven heating and incomplete results.

For medical equipment such as surgical instruments, diagnostic equipment, catheter systems, laboratory equipment and sensors, the plastic should be medical grade and heat shrinkable.

Heat shrink tubing material may be thin-walled or dual wall. The former is used for insulation, strain relief and protection against mechanical damage and abrasion and the latter as a corrosion protector and sealant. Microtubing, i.e. tubing for fine-gauge wires, requires lower shrink temperatures, higher strain relief and better bonding properties. Tubing materials used for industrial applications should be capable of withstanding the influence of industrial fuels, solvents, and chemicals.

You would have noticed heat shrink tubing on wire harnesses and splices and insulating terminals. Mostly PVC is used because it is cheaper, flame retardant, and resists sunlight, fungus, moisture and most chemicals and oils. Polyolefin, another type of heat shrink tubing materials is very flexible and is used for multi-purpose insulation.

As with any consumer products, you can choose a tubing material from a variety of colors to make your insulation look organized, neater, and professional.

Price per foot can start at $0.95 per foot on a 50' spool. The ratio of shrinkage varies between 2:1 and 4:1