When the wire is made, it needs a layer of foil inside, and the outside is insulated. Why is that?
An aluminum foil plastic composite #, used as a shield cable. The cable foil requires less oil on the surface and has no holes. It has high mechanical properties, but the overall quality requirements are not high, but the requirements of the length are very strict.
Insulation is done outside to protect or leak electricity.The cable foil is coated with plastic film on one or both sides with the tightness and shielding of aluminum foil
Wire, usually used as a signal wire, is used as a shield to reduce interference from external signals to the transmitted signal;
