Application of Thermal Shrinkage Casing in Cable Welding

- Sep 23, 2019-

Cables, as the intermediate links connecting various functional components of the whole electronic system, are widely used in both aerospace and offshore platforms. They are distributed in a variety of working environments, and the stability of their performance is particularly important. Because any bad contact or poor welding quality will have an inestimable impact on the whole system. Cables are like human blood vessels and nerves. Problems in the main blood vessels and nerves of the human body will lead to human death. The unreliable and unsafe cables will affect the realization of the functions of the whole system.

In order to protect against moisture and dust, a layer of shrinkable sleeve should be heat-shrinkable at the junction between the connector and the cable. The selection of the shrinkable sleeve should be based on the size of the tail accessories of the connector and the outer diameter of the cable. The length of the shrinkable sleeve should be from the outer sleeve of the connector to the length of the cable that can shrink part of the cable. The length of the shrinkable cable generally has the outer diameter of the cable. It's about two times as good. For example, the diameter of 6 cm cable, thermal shrinkable sleeve to shrink about 10 cm cable.

When all the cores are welded, the spare wires are wrapped up with heat shrinkable sleeves. Tighten the tail cover, tighten the top wire, wrap several layers between the cable surface and the tightening ring with insulating tape, pull out the core shielding layer or the inner shielding layer, make a cold-rolled end, connect it to a screw of the tightening ring, then tighten the screw at both ends of the tightening ring ring ring, and flatten the cushion. After the tail cover is finished, it should be tightly connected with the cable and not shake. Shrink the heat shrinkable sleeve to the highest position that may hinder the rotation of the outer screw sleeve. The other section shall cover the cable at least 2 times of the cable diameter. If the cable diameter is too thin, and the tail structure size of the electrical connector is too large, and the cable can not be retracted after the tail is tightened, then a relatively thin heat-shrinkable sleeve should be retracted on the tail of the last heat-shrinkable sleeve to tightly integrate it with the cable. Finally, the cable marking is retracted 5 cm away from the tail of the thermal shrinkable sleeve or the tail of the electrical connector. When the cable is retracted, attention should be paid to keeping the written side of the cable marking consistent with the position of the electrical connector No. 1, that is, on a horizontal plane. And it is better to use a hot air gun to blow from the back of the sign when it is heat-shrinking, so that the heat-shrinking sign font will not shrink too much, leading to unclear and difficult to identify.


The heat shrinkable casing involved in this paper can be divided into two categories.

The inner wall with thermosol is used to protect the connection between electrical connectors and cables. The adhesive on the inner wall of the thermoshrinkable sleeve with glue will melt after heating, and it has good moisture-proof effect after cooling, and has certain hardness.

One kind is the heat-shrinkable casing with no glue on the inner wall, which is softer after heat-shrinkage. One kind is the taped packaging, which can be printed and marked, and used as the marking casing. One is the transparent thermal shrinkable sleeve used to protect cable marking, which is often used to identify the protective sleeve. Another is that it can be used for end protection of standby wires and end protection of core shielding layer.

The use of heat-shrinkable sleeve should take full account of the size before and after heat-shrinkage, that is to say, the size before heat-shrinkage must be slightly larger than that of the package, and the size after heat-shrinkage must be smaller than the total outer diameter of the package, so as to ensure the use effect of heat-shrinkable sleeve.