7 knowledge points that heat shrinkable tubes must know! The main knowledge points include inner diameter, wall thickness, shrinkage rate, shrinkage temperature, final shrinkage temperature, and working temperature. For 7 aspects such as color, Yeva Advanced Materials will analyze and introduce you specifically.

1. Inner diameter

We know that the cross section of the casing is cylindrical and the inner diameter is the size of the inner diameter of the pipe wall, that is, the distance between the inner walls. We usually use the letter Φ to indicate it, because Φ is used to mark the diameter in engineering. Then it is followed by a number, indicating the value of the inner diameter. If the unit is not written by default, it is MM mm, for example Φ6.

2. Wall thickness

The second parameter wall thickness refers to the thickness of the tube wall, and the inner diameter reflects the size of the tube. What does this wall thickness refer to? Intuitively speaking, it is the thickness of a thing. So what does the thickness affect? We know The function of the heat shrinkable tube is insulation protection. The thickness of the heat shrinkable tube affects the size of the insulation protection. We all know that the clothes are thick, so the effect of cold protection and warmth is great. The wall thickness affects its protective ability, so on the whole, the thicker the heat shrinkable tube, the better its mechanical protective ability.

3. Shrinkage rate

The heat shrinkable tube will shrink when heated, and only things that shrink will have this parameter. The shrinkage rate is sometimes called the heat shrinkage rate, heat shrinkage ratio, etc., which refers to the diameter of the heat shrinkable tube at room temperature, such as Φ6 , The diameter after heating shrinkage is for example Φ3, then the shrinkage rate we call is the ratio of the inner diameter of the heat shrinkable tube before shrinking to the inner diameter after shrinking, that is, 6/3=2/1, this 2:1 It is the shrinkage rate of the casing, which reflects the shrinkage capacity of the heat-shrinkable casing. The higher the shrinkage rate, the thinner the heat-shrinkable casing is fully contracted. If the heat shrinkable tube is Φ6 before shrinking and Φ2 after shrinking, it is only two millimeters in size, then its shrinkage ratio is 6:2, which is 3:1.

If it is 1.5mm after shrinking, then the shrinkage rate is 4:1. The common shrinkage rates of heat shrinkable tubes are 2:1, 3:1, 4:1; when it comes to shrinkage, we will continue to talk about the wall. Thickness, just like cowhide tendons, the wall thickness will be thin when it is stretched, and the wall thickness will be thick after shrinking. After the same heat shrinkable tube shrinks, the wall thickness will also increase, which is more important for the heat shrinkable tube The wall thickness refers to the wall thickness of the heat-shrinkable tube after shrinking, because it is the state that our heat-shrinkable tube plays a protective role under the real heavy working state. The shrinkage rate of the heat shrinkable tube refers to the radial shrinkage rate, because in principle, for the heat shrinkable tube, it is theoretically not allowed to change in the longitudinal direction.

4. Shrinking temperature

On the surface, it is the temperature at which the heat shrink tube begins to shrink. We start heating the heat-shrinkable tube. When the heat-shrinkable tube starts to react, the temperature at which the shrinkage reaction just begins. Our general PE heat-shrinkable tube begins to shrink when the shrinkage temperature is 84°C. .

5. Final shrinkage temperature

It refers to the temperature at the end of the contraction, which can make the heat shrinkable tube reach the temperature of complete shrinkage. For example, our heat shrinkable tube is heated to 84°C. It is not like cowhide tendon. I just need to hold it to how big it is. The tendons immediately bounced back completely and returned to their original state. Our heat-shrinkable tube is not like this. When it is heated to 84℃, it will not immediately change back to its original shape like cowhide tendons. The shrinkage of our heat-shrinkable tube is a gradual process. We heat the heat-shrinkable tube to 84 ℃, it just has the shrinkage reaction, it can not completely shrink the heat shrinkable tube, we must continue to heat it to the final shrinking temperature, if it is 120 ℃, then it can be completely contracted.

6. Working temperature

This temperature is an important parameter that runs through the heat shrinkable tube. The working temperature sometimes refers to the rated temperature, which refers to the temperature at which the casing can work normally and continuously. The first two temperatures refer to the temperature when the processed heat shrinkable tube can shrink and reflect. , Let’s take the Φ6 heat-shrinkable tube as an example.

Slowly heat the heat shrinkable tube with a hot air gun. When the temperature reaches 84℃, the heat shrinkable tube begins to shrink, and then slowly shrinks to Φ5, Φ4. When the temperature reaches the final shrinkage temperature of 120℃, the heat shrinkable tube completely shrinks to Φ3 , Shrink tightly on the object, and then the process of processing and heating is over, and then install the part covered with the heat shrinkable tube on the air conditioner, etc., and perform normal work. Its normal working environment, for example, we set The normal working temperature of the tube is -55℃ to 125℃, because we know that many times the product will be sold to various places, some places are relatively cold, some places are relatively hot, then it has a certain scope of application, our The nominal temperature of the product indicates that it can be used normally at this temperature. Once it exceeds the normal use temperature, the life span may not be guaranteed, and it may not work normally. The normal temperature we are talking about here means that the heat shrinkable tube can function. Insulation protection, exceeding this temperature may not be able to play a role.

7. Color

Needless to say, the color of the heat shrinkable tube, there are conventional ones to choose from.