Key knowledge points of silicone rubber cold shrink tube

As we all know, silicone rubber has the characteristic of "elastic memory", just like a spring. The cold shrinkage technology is also called pre expansion technology, that is, the silicone rubber is pre expanded within the elastic range by mechanical means, and is sleeved into the plastic support strip for fixation. During installation, only the plastic support strip needs to be removed, and the silicone rubber will shrink quickly and be clamped on the cable body.

Silicone rubber cold shrink tube takes advantage of the excellent weather resistance and good resilience of silicone rubber. The cold shrink tube is an ideal sealing material for low-voltage power cable connection, wireless communication tower and other exposed coaxial connections, and plays a good sealing and waterproof role.

Key knowledge points of silicone rubber cold shrink tube:

Expansion rate

The expansion rate refers to the degree of change of the inner diameter of the prefabricated rubber body after it is expanded, that is, the ratio of the expanded inner diameter to the unexpanded inner diameter. The larger the expansion rate, the greater the radial pressure generated after contraction, and the better the electrical performance and waterproof sealing performance of the interface, that is, the safer and more durable.

Permanent deformation rate

The permanent deformation rate refers to the degree of change of the inner diameter of the rubber tube after shrinkage to the original inner diameter before support after temperature change and long-term storage due to the elastic memory of the rubber material. The smaller the permanent deformation, the better the memory of the rubber elastomer. After long-term storage, the rubber elastomer installed on the cable can still ensure sufficient radial pressure on the main insulation interface of the cable, thus ensuring long-term safe operation life.

Interference

Dr=（D-d）/d *100%

Dr: interference

D: Cable outer diameter

d: Inner diameter of cold shrink tube after free contraction

The larger the interference of the silicone rubber cold shrink tube with respect to the cable, the greater the radial pressure of the cold shrink tube on the cable, and the higher the discharge level along the cable interface.