What Is Meant By Sheath Of Cable?

What is meant by sheath of cable?

The cable jacket is the outermost layer of the cable and serves as the most important barrier in the cable to maintain the safety of the internal structure, protecting the cable from mechanical damage during and after installation. Cable jackets are not meant to replace the reinforced armor inside the cable, but they can provide a reasonably high level of protection with limited means. In addition, the cable jacket provides moisture, chemical, UV and ozone protection.

But what kinds of cable jacket materials are there? There are many varieties of cable jackets, and the selection of the raw materials of the cable jackets should take into account the compatibility of the use of connectors and the adaptability to the environment. For example, extremely cold environments may require cable jackets that remain flexible at very low temperatures. The typical characteristics of some of the most common sheath types are listed below, so let's take a look!

1. Cable sheath material: PVC

The cable material is a particle prepared by mixing, kneading and extruding with polyvinyl chloride as the base resin, adding stabilizers, plasticizers, inorganic fillers such as calcium carbonate, additives, and lubricants. Polyvinyl chloride can be manufactured to work in a variety of environments and applications. It is low cost to use, flexible, properly sturdy, and has fire/oil resistant materials. However, this material contains substances that are harmful to the environment and human body, and there are many problems when used in special environments. With the enhancement of people's awareness of environmental protection and the improvement of material function requirements, higher requirements are put forward for PVC materials.

2. Cable sheath information: PE

Polyethylene is widely used as a coating material for wires and cables due to its excellent electrical insulation properties and excellent processing properties, and is mainly used in the insulation and sheathing layers of wires and cables. Excellent electrical function and very high insulation resistance. Polyethylene can be strong and very stiff, but low density PE (LDPE) is more flexible. Properly manufactured PE has excellent weather resistance. The linear molecular structure of polyethylene makes it easy to deform at high temperature. Therefore, in the application of PE in the wire and cable industry, polyethylene is often transformed into a network structure by cross-linking, making it also strong at high temperatures. Deformation resistance.

Cross-linked polyethylene (XLPE) and polyvinyl chloride (PVC) are both used as insulation materials for wires and cables, but XLPE wires and cables are more environmentally friendly than PVC wires and cables, and they have better performance.

Cable acceptance requirements:

(1) The iron or wooden reel on which the cable is wound should be intact, and the surface of the iron reel or wooden reel should have a factory label, and the label should indicate the manufacturer's name, performance standard, cable name, specification model, rated voltage, and cable length. , gross weight, reel number, date of manufacture, arrow indicating the correct direction of rotation of the cable reel.

(2) The cable identification should be clear, complete and complete, and some cables should have the special marking line of the manufacturer, or a marking tape with the name of the manufacturer and the year of manufacture printed within every 300mm.

(3) The anti-corrosion maintenance layer on the surface of various cables should be free of defects such as cracking, mechanical damage and flattening; the bare steel tape armor should be lubricated and flat, no rust and coated with asphalt oil; the petroleum asphalt of the maintenance layer should not be melted or lost. phenomenon; the surface of the load-bearing detection cable should be lubricated and rounded, and there should be no wire jumping, scratches, or corrosion.

(4) Both ends of all kinds of oil-impregnated paper insulation and oil-filled and air-filled cables should be well sealed, and there should be no leakage.

(5) The cable should be wound tightly and neatly on the cable reel, and there should be no slack crossing. The diameter of the cable reel should not be less than 50 times the outer diameter of the cable; Nail the maintenance box to prevent abrasion, fix one end of the outer layer on the inner side, and nail the maintenance plate around the packaging tray.