Abstract: A field-controlled composite insulator uses materials which are greatly stressed by an inhomogeneous distribution of an electrical field across a surface thereof. One of the causes thereof is the structural configuration of the insulator. The field strength changes particularly in a region of fittings due to a transition from insulating materials of sheds and an insulator core to a metal material, due to a transition from ground potential at cross members or to a conductor potential at that location, where conductor cables are attached. A further cause is deposits of dirt, which stress an insulator overall. A field control layer is therefore disposed between the core and the protective layer in at least one section of the insulator. The control layer includes particles as a filler, which influence the electrical field of the insulator. A method for producing the composite insulator is also provided.

Abstract: The invention relates to the production of composite insulators consisting of a shank in the form of a bar or a tube, which is provided with a covering and which comprises plate-like screens which are distanced from each other. The covering and the screens are made of an elastomer material with high insulating qualities. As a result, the number, distance, form and size of the screens can vary from insulator to insulator. According to the invention, at least one injection mould (10a, 10b, 11a, 11b, 12a, 12b, 13a, 13b) for injecting a screen (2, 3, 4, 5, 19, 20, 21, 22) is arranged downstream from a device which is used to provide the shank (1) with a covering. The injection mould can be advanced in order to inject a screen upon the shank and opened in order to unmould said screen. An advancing device is also provided in order to displace (16) the shank (1) or the screen mould.