All kinds of plastic wire and cable laying, will be the role of a variety of mechanical forces, such as bending, stretching, twisting, positive pressure, shock and vibration, etc.. All external mechanical forces applied to the cable will cause some damage to the cable. In order to protect cable structure and electrical properties, improve the service life of the cable, the cable in support layer increases the armor layer is very necessary of.
Armoured cables are usually two, and steel wire armored armored.
To allow the cable can bear radial pressure, using double strip, gap winding process, said steel tape armored cable; cable is the steel tape wrapped on the cable core, then extruding the plastic sheath. Said method such as KVV22 this type of cable control cable, communication cable, plastic power cable VV22, SYV22, etc.. The cable type subscript two Arabic numerals, the first: "2" said double steel tape armor; the second: "2" said PVC sheath, such as polyethylene sheath to "2" changed to "3". This type of cable is mainly used in the general bearing high pressure situations. For example: crossing roads, squares and large compared to the side of the road, the railway side vibration, suitable for underground, tunnels and wear pipe laying.
In order to make the cable can withstand large axial tension, adopts a plurality of low carbon steel wire winding process, called steel wire armored cable. Into cable after the steel wire according to certain distance wrapped on the core wire and then squeeze sheath, the cable model representation methods, such as control cable KVV32, plastic power cable VV32, coaxial cable HOL33 etc.. Models of two Arabic numerals, the first: "3" said fine steel wire armoured; the second: "2" said PVC sheathed, "3" said polyethylene sheath. This type of cable is generally used in large span, laying a large gap between the occasion.
