Mr. Gehrig studied material science at the Swiss Federal Institute of Technology in Zurich. He then worked for 9 years as Leader of the Application Laboratory for Electrical Applications at resin supplier, Ciba-Geigy. He later worked as Managing Director of an equipment supplier and mold maker. Currently, he serves as Sales Engineer and Project Manager at one of the leading suppliers of mixing and dosing equipment for thermosetting materials.
Components used for MV and HV applications are exposed to high electrical loads and their insulation materials must be free of defects such as voids or air bubbles. However, liquid silicone rubbers are sometimes processed without vacuum pre-treatment to de-gas the basic components. This presentation describes the benefits of vacuum treatment with special attention to parts having large volume as well as on the machinery required. The focus will be on casting or injection of insulation components featuring a high shot weight of silicone material, e.g. cable joints or hollow core insulators where shot weights of LSR vary from 20 to 70 kg.