Heat shrink tubing is available in a broad range of types and sizes, and is used for a broad range of applications. Read here for which applications heat shrink tubing is used, which types there are, and when which type is used, in this complete overview!
Types of heat shrinkable products
Heat shrink tubing is a heat shrinkable product. Heat shrinkable products are products which, as the name says, shrink when they are exposed to heat. These products are made by stretching plastics such as polyolefin during the production process. By heating the stretched product, it shrink back to its original size. In basis, three types of heat shrinkable products can be distinguished:
- Heat shrink tubing
- Heat shrinkable fibre optic splice protectors
- Heat shrinkable moulded parts
Heat shrink tubing
Heat shrink tubing is probably the most well-known type of heat shrinkable product. Heat shrink tubing is a tube, often made of polyolefin, which shrinks when heated.
Heat shrinkable fibre optic splice protectors
Also called heat shrinkable connectors. This product shrinks when heated and is used to repair broken fibre optic cables and to create new connections, from one fibre optic cables to another.
Heat shrinkable fibre optic splice protectors consist of three parts: a steel rod, to stabilize and protect the connection, an inner tube which shrinks when heated to make the connection, and an outer tube, which shrinks around the steel rod and the inner tube, to keep the steel rod and the inner tube tightly together.
Heat shrinkable moulded parts
Heat shrinkable moulded parts have a, per type differing, shape which is used for specific applications, such as splitting cables which come out of one housing, or to close off open cables.
Heat shrink tubing is, out of all of the heat shrinkable products, used the most. For this reason, in this blog we will zoom in on heat shrink tubing specifically and the available types, the different applications and the properties of heat shrink tubing.
For which applications is heat shrink tubing used?
Heat shrink tubing is used for a number of different applications, namely:
- The protection of cables
- The repair of cables
- Identifying cables
The most common application is protecting cables. By shrinking heat shrink tubing on a cable, an extra layer of protection is created around the cable. Heat shrink tubing offers five types of protection:
- Mechanic protection: protecting the cable against wear, dents and ruptures.
- Electrical protection: insulating the cable.
- Thermal protection: some types of heat shrink tubing are self-extinguishing or flame retardant, making the cable better resistant against damage due to fire.
- Chemical protection: some types of heat shrink tubing are resistant to acids, salts, chlorides and other chemical substances, and can protect cables against these substances.
- Environmental protection: heat shrink tubing can protect against UV radiation, corrosion, and sometimes offers watertight sealing – especially the types with adhesive.
Another common application is cable repair. When a cable is damaged, using heat shrink tubing is an easy way to repair the cable – provided the wires in the cable are still intact.
Finally, heat shrink tubing is sometimes used to mark cables, or to provide them with identification. By using a specific / obvious colour, cables can easily be marked. In addition, heat shrink tubing is available in a transparent version as well, using which a label on a cable can still be read after using heat shrink tubing on the cable. Finally , a number of heat shrink tubing types are printable. The heat shrink tubing is printed, after which it is shrunk on a cable. The print shrinks along with the tube, and remains readable.
The different types of heat shrink tubing
Heat shrink tubing can be divided in separate types in a number of ways. Different types can be distinguished based on the wall thickness (thin-wall, medium-wall and heavy-wall) and based on the material of which the heat shrink tubing is made (crosslinked fluoroelastomeer, crosslinked polyolefin, crosslinked co-extruded adhesive lined polyolefin, crosslinked adhesive lined polyolefin, crosslinked PVDF, modified polyolefin, modified tetrafluoroethylene).
Read more about the different wall thicknesses and about the material types of which heat shrink tubing is made below.
Different types of heat shrink tubing – wall thickness
Heat shrink tubing is available in three wall thicknesses: thin-wall, medium-wall and heavy-wall.
- Thin-wall heat shrink tubing has a wall thickness ranging from 0,4 up to 0,82 millimetres and is often used in the electrotechnical industry for low voltage applications. The thin wall of thin-wall heat shrink tubing results in the tube being more flexible than is the case with medium-wall and heavy-wall heat shrink tubing. However, thin-wall heat shrink tubing offers less protection against cuts and other types of mechanical damage.
- Medium-wall heat shrink tubing has a wall thickness ranging from 1,6 up to 3 millimetres – depending on which variant is chosen.
- Heavy-wall heat shrink tubing has a wall thickness after shrinking ranging from 3,2 up to 4,7 millimetres.
Different types of heat shrink tubing – material quality
The material of which heat shrink tubing is made depends on the desired properties of the heat shrink tubing. Some material types are halogen free, other material types are self-extinguishing. Read more about the specific material types of which our heat shrink tubing is made below.
Crosslinked polyolefin
The most commonly used material type for heat shrink tubing is ‘crosslinked polyolefin’. Among others, the H-2(Z), the most popular type of heat shrink tubing, is made of crosslinked polyolefin. This material is UV resistant, but not halogen free. Also, this material type is self-extinguishing.
Crosslinked co-extruded adhesive lined polyolefin
Two material types are very similar: crosslinked adhesive lined polyolefin, and crosslinked co-extruded adhesive lined polyolefin. These material types only differ from crosslinked polyolefin due to the adhesive lining that these material types have. These two specific adhesive lined material types differ from each other in the way in which the adhesive lining is produced. With crosslinked co-extruded adhesive lined polyolefin, the adhesive lining is molten onto the heat shrink tubing. This is not the case with crosslinked adhesive lined polyolefin.
Modified polyolefin
Modified polyolefin is a plastic used for medium-wall busbar insulation tubing, due to the excellent creep current resistance and the electrical properties of this material type. Our heat shrink tubing made of modified polyolefin has a red colour and is both UV resistant and halogen free.
Crosslinked fluoroelastomeer
Fluoroelastomeer is also called Viton® and offers superior cut-, impact- and wear resistance. This makes this material perfect for use in applications where a high resistance to fuels, lubricants, acids, solvents and corrosive liquids is required. UV resistant due to its black colour, not halogen free.
Crosslinked PVDF
Crosslinked PVDF is a plastic produced by Kynar®. Kynar® PVDF has a longer lifespan than the material types named above and offers excellent resistance against the most aggressive solvents and chemicals, high mechanical strength and a high wear resistance. In addition, Kynar® PVDF is resistant to fire, resistant to UV and nuclear radiation and can resist high temperatures: up to a continues operating temperature up to 150 °C.
Modified polytetrafluoretheen
Modified polytetrafluoretheen (PTFE) is also called Teflon® - well known for the non-stick coating in frying pans. Due to heat shrink tubing made of PTFE offering good stability under high temperatures, resistant is to chemicals and flame retardant is, heat shrink tubing made of this material type are often used in the automotive, military and aerospace industry.
Heat shrink tubing properties – shrink ratio
Different types of heat shrink tubing have different shrink ratio’s. The shrink ratio indicates in which proportion the tube shrinks in diameter when heated. A tube with a 2:1, 2-to-1 shrink ratio, and an inner diameter (before shrinking) of 1,2 millimetres, will have an inner diameter of 0,6 millimetres after shrinking.
The shrink ratio can range from 1,5:1 to 6:1, depending on the type of heat shrink tubing. We have heat shrink tubing types with the following shrink ratio’s in our assortment:
Heat shrink tubing properties – shape, inner diameter and type of packaging
A number of properties are universal for all types of heat shrink tubing, regardless of the material of which the heat shrink tubing is made, what the wall thickness is, or for which purpose the heat shrink tubing is used. Read about these properties below.
Shape
Heat shrink tubing is available in two shapes: flat and round. The shape has no influence on the performance or functioning of the heat shrink tubing. Heat shrink tubing with a diameter up to 6,4 millimetres is always round, to make use easier. Heat shrink tubing with a diameter ranging from 6,4 up to 16 millimetres is available both flat and round. Heat shrink tubing with a diameter of 16 millimetres or higher, is always flat. Otherwise, it would be impossible to sell these sizes on a reel.
Inner diameter
The inner diameter is of importance when choosing the right size of heat shrink tubing. Always choose a diameter which is, after shrinking, a little bit smaller than the diameter of the cable. When a cable, for example, has a diameter of 9 millimetres, choose heat shrink tubing with an after shrink diameter of 8 millimetres, so that the heat shrink tubing fits tightly around the cable.
Packaging type
Heat shrink tubing can be supplied in three packaging types:
- On a reel
- Minibox
- Length pieces
Keep this in mind when ordering heat shrink tubing. Length pieces are mostly used for shorter pieces of heat shrink tubing – up to 1,22 metres. Heat shrink tubing is delivered on a reed when it concerns longer pieces – up to 150 metres.
A minibox can be compared to heat shrink tubing on a reel, with the main difference that the reel in a minibox is shorter (5 or 10 metres) and that the reel is packaged in a box, hence ‘minibox’. This way, the box an easily be used as a dispenser, in a workplace for example.
The properties per heat shrink tubing type can be found in expansive overviews on our product pages. Do you need help in finding the right type of heat shrink tubing? View our flowchart for easily finding the right type of heat shrink tubing.
Are you still not sure which type of heat shrink tubing you should choose? Our advisors are happy to help! Contact them for tailored advice.
Curious which types of heat shrink tubing we offer? View our full assortment here.
