| 摘要 |
PURPOSE:To manufacture an electrically insulating homogeneous rubber composition having no void by providing a temperature gradient sequentially reducing toward an outer metal mold or core rod when the composition is vulcanized and molded between the mold and the rod. CONSTITUTION:In a metal mold, a hollow core rod 2 which becomes an inner metal mold is coaxially disposed in a bell-like outer metal mold 1. After the surface of the rod 2 is mold-release-processed, its center is covered with a semiconductive rubber layer 6 which becomes an inner semiconductive layer, and coaxially disposed in the mold 1. Then, vulcanizable electrically insulating rubber composition 3 is filled between the mold 1 and the rod 2, heated while feeding cooling water from one end to the other end of the rod 2 thereby to vulcanize the composition 3. Voids 5 are moved as the vulcanization is advanced, and completely vanished after the vulcanization is completed. |
