| 摘要 |
PURPOSE:To obtain a cured product with high reliability electrically and mechanically by a method wherein the residual stress in the cured product is relieved by producing such a temperature gradient that the temperature at the lower part of resin is higher than that at its upper part by means of a heat source equipped in a mold vessel. CONSTITUTION:Firstly, fiber material 1 is wound around a mandrel 2. Secondly, the resultant wound fiber material 1 is placed in a mold 3. Thirdly, the total assembly is placed in a tank 4 in order to pour resin 6 through a resin well 5 installed outside the tank 4. Fourthly, heaters at lower position among vertically split heaters 7, which are mounted on the inner peripheral side of the mandrel 2, are energized so as to control the temperature at the lower part of the resin higher by 5-20 deg.C than that at its upper part. After that, heaters 7 at higher position are successively energized. Because the temperature at the lower part of the resin is made higher than that at the upper part of the resin, the resin at the lower part starts to cure earlier than that at the upper part. At this time, the cure shrinkage has already started. However, because un-cured resin exists above the cured resin, the un-cured resin flows in the shrunk portion and consequently no substantial cure shrinkage exists and the major portion of strain due to the cure shrinkage can be released. |
