Rubber Insulation

Used for power cables of up to 1 kV and usually applied by ex­truding the rubber around the conductor. Another method is to pass the conductor sandwiched between two rubber tapes through grooved rollers that pressure-weld the rubber to form an insulating layer. The longitudinal machine used to carry out this process has two or three sets of rollers in series to apply layers of rubber to a number of conductors simultaneously.