Method of building an insulation system around a naked conductor section of a power cable

A method of building an insulation system around a naked conductor section of a power cable, which power cable has a conductor which includes the naked conductor section and which power cable comprises an insulation system already provided around a majority of the conductor, which insulation system comprises an inner semiconducting layer arranged around the conductor, an insulation layer arranged around the inner semiconducting layer, and an outer semiconducting layer arranged around the insulation layer, and wherein the method comprises:

• a) placing the naked conductor section in a mold, and
• b) moulding an insulation system around the naked conductor section, wherein the molding of the insulation system involves injecting a first semiconducting compound into a first mold cavity to form an inner semiconducting layer around the naked conductor section, injecting an insulation compound into a second mold cavity to form an insulation layer around the inner semiconducting layer, and injecting a second semiconducting compound into a third mold cavity to form an outer semiconducting layer around the insulation layer,
• wherein the mold comprises a ring-shaped runner system having a ring-shaped runner which in the beginning of each mold cycle only has a single gate opening, which single gate opening is located opposite to a sprue, and
• wherein the mold comprises a movable sleeve arranged in a first position at the beginning of each mold cycle thereby forming the single gate opening, wherein the method comprises moving the sleeve axially from the first position to a second position to obtain a gate along the entire circumference of the ring-shaped runner, wherein the sleeve is moved from the first position to the second position when any of the first semiconducting compound, the insulation compound and the second semiconducting compound has reached the single gate opening.