However, not all workpieces experience the same vacuum value due to the hydraulic pressure of the impregnating agent. This reduces the vacuum by 2.6 mbar per 25mm filling level. With a filling height of 1,000 mm, there is a pressure difference of 100 mbar. As a result, the penetration results for castings can vary depending on the position in the batch basket.
Nevertheless, this process achieves very good results for sintered parts and electrical components (e.g. plastic connectors) and is therefore one of the preferred methods of impregnation. Dry vacuumimpregnation is preferred for castings.