The connection and difference between the cable isolation sleeve and the inner lining

In the production and manufacturing process of cables, the two concepts of isolation sleeve and inner lining are often encountered. The so-called isolating sheath is the sheath between the coating layers of two different metal materials, which is commonly referred to as the inner sheath. The inner lining is the core and filler (if any) of the multi-core cable. The non-metallic cladding layer on the outside and under the protective layer.
Isolation sleeve: The focus is on the word isolation. The isolation is between two different metals, such as the three-core YJV22 structure. There is a layer of PVC between the copper strip and the steel strip. At this time, the PVC plays the role of isolation. From chemical and physical From the perspective of consideration, the activities of copper and iron are different, and when they are in contact with each other, they will accelerate the oxidation of copper. Therefore, the isolation sleeve must be squeezed and cannot be wrapped, because there are gaps in the wrapping, which may cause mutual contact.
Lining layer: copper wire shielding, copper tape armoring, single-core power cable-this structure also has PVC between the shielding layer and the armoring layer, but since the two metals are of the same kind, they will not accelerate oxidation, so PVC does not need to be used. To the isolation effect, so in this case it is not called an isolation sleeve, but an inner liner. In addition, the inner liner may be wrapped.
Cushion: Generally, the word "wrap tape" is added in front of the cushion. This is used in many standards to describe its function. When the cable is armored, it is used together with the inner lining to strengthen the inner lining. The role of.
The inner lining can be squeezed or wrapped, while the isolation sleeve can only be squeezed. For cables with specifications above 10mm2, wrapping can save material costs. When the metal layer under the armor is different from the armor material, a layer of isolation sleeve must be squeezed to separate it. At this time, the isolation sleeve can replace the inner lining. Since the cores of medium voltage power cables are shielded by copper tape, and the cores of low voltage cables are unshielded, this is why we usually see why medium voltage armored cables have to squeeze the inner lining (isolation sleeve), while low voltage armored cables The reason to wrap the inner liner.http://www.rfcable.com.cn/en