What is heat shrink tubing?

    The literal meaning of heat shrink tube is very easy to understand. It is a sleeve that shrinks when exposed to heat, so it is called heat shrink tube for short. Next, let’s take a look at the principle of heat shrink tubing. Why does it have the function of shrinking when exposed to heat?

Heat shrink tube principle

    During production, the heat shrinkable tube is heated to a high elastic state and a load is applied to expand it. This can also be understood as applying pressure from the inner wall to achieve the purpose of expansion in the high elastic state. Cool quickly while maintaining expansion, and then maintain this expansion state. At this time, the heat shrinkable tube is considered to be produced. Once heated during use, it will return to its highly elastic state, but now the pressure on the inner wall is gone, and it will retract to tightly wrap the product that needs protection.

    To put it simply, it is a heat shrinkable sleeve that shrinks after heating, and the inner diameter becomes smaller. It can also be understood as a rubber band. When it expands, it is like a person holding it with his hands, pulling the rubber band open, and then quickly fixing it. When heating, loosen the handle to shrink it, the same principle.

    Here are some pictures for demonstration to facilitate your understanding. The inner diameter before shrinkage is 6mm, and the inner diameter after shrinkage is only 3mm. After cooling at room temperature, the inner diameter will always be fixed at 3mm and cannot be expanded unless professional production equipment is used.

 The heat shrink tube before shrinking is the finished product

Shrunk heat shrink tube