How to choose the right heat shrink tube?
Heat-shrinkable tube, also known as heat-shrinkable tube, is a special type of tube. It is widely used in insulation protection, rust prevention, and corrosion prevention of various wire harnesses, solder joints and inductors. It is a kind of cable and connector. Excellent tool for minor repairs. Heat Shrink Tubing has the special function of shrinkage due to heat. Before choosing the proper heat shrinkable tube, it is important to understand the product's characteristics and key parameters for correct application.
Figure 1 Heat shrink tubing protects the terminal area from contamination and identifies circuits by color coding
Figure 2 Heat shrink tubing can be used to repair damaged wires and cables
There are large and small heat-shrinkable tubes on the market. How to choose the right heat-shrinkable tube? We can use different parameters of the heat-shrink tube in the Digi-Key official website.
Figure 3 Different parameter options for heat shrink tubing in Digi-Key's official website
Parameter one
the inside diameter of
the inside diameter of
We can use the vernier or a ruler to measure the maximum and minimum diameters of the coating. Afterwards, when selecting the inner diameter of the heat shrinkable tube before shrinking, that is, the “ID (factory)” parameter in the Digi-Key official website, the maximum inner diameter can be used as a reference and an additional about 20 to 30 percent more. You can. This extra twenty to thirty percent will allow the heat-shrink tube to have enough space through the protruding position.
Figure 4 heat shrink tube with different inner diameter
Using the measured minimum diameter, you can find the dimensions of the heat shrinkable tube that can be wrapped around the object after heat shrinkage, that is, the "inner diameter - after recovery" parameter in Digi-Key's official website. How to choose this size? It should be smaller than the size of the object to be wrapped, so that the heat shrinkable tube can be tightly contracted on the object.
"Internal (factory)" and "Inner diameter - post-recovery" within Digi-Key's official website have different meanings:
Inner diameter (factory)
Also known as the inner diameter before shrinkage, the manufacturer provides the smallest inner diameter of the shrink tube before it encounters heat. This means that if the material is a 1/4" ID, the heat shrink tubing will be shipped with a minimum internal diameter of 1/4" and there may be some micro tolerances.
Inner diameter - after recovery
Also known as the inner diameter after shrinkage, it means that the heat shrinkable tube can shrink to its maximum inner diameter when it is exposed to heat. Even if the heat shrink tube has a slightly higher dimension before shrinking, the heat shrinkable tube will shrink to at least this inner diameter specification when heated.
Figure 5 Shrinkage, Length, and Inner Diameter Parameters of Heat Shrink Tubing in Digi-Key's Official Website
Parameter two
Shrinkage
Shrinkage
We can also use the "shrinkage" parameter within Digi-Key's official website to screen suitable heat shrink tubing. There are many “shrinkage” options for heat shrink tubing in the Digi-Key website, such as 1.2 to 1, 1.3 to 1, 1.5 to 1, ..., 6 to 1, etc.
Please note that high shrinkage means that heat-shrink tubing is suitable for larger items, such as connectors, and then heat shrinks to a smaller wire diameter. In general, it is recommended that the heat shrink tubing size be no more than 40% of the scale. This allows the shrink tube to effectively shrink and wrap the object.
Parameter three
length
length
Please note that the heat shrinkable tube will shrink by 5% to 7% at the same time when it is heated. Therefore, when the length of the heat shrink tube is selected, additional adjustments are required.
Parameter four
Wall thickness after recovery
Wall thickness after recovery
Heat Shrink Tubing has various thicknesses. Thicker heat shrink can provide better wear resistance, stronger and more resistant to wear. If you do not need heat-shrinkable tubes with high abrasion resistance, a thin-walled heat-shrinkable tube can be used.
Other parameters
Material, working temperature and shrinkage temperature
Other parameters
The material of the heat shrink tube is closely related to the temperature of its use environment. Such as the shrinkage temperature of 340 °C, a PTFE (polytetrafluoroethylene) heat shrinkable tube, with wear, chemical resistance, corrosion resistance, flame retardant, heat resistance, anti-ultraviolet radiation characteristics.
Figure 6 Material, Operating Temperature, and Shrinkage Temperature Options for Heat Shrink Tubing in Digi-Key's official website
to sum up
In short, when choosing the right heat shrink tube, please pay attention to the following elements:
First: The size of the wrapper.
Second: The characteristics and uses of heat-shrink tubing, such as: thickness, shrinkage, working temperature, shrinkage temperature, etc.
