| 摘要 |
PURPOSE:To mold a highly accurate plastic molded article through a curtailed molding cycle, by a method wherein a mold temperature measured on the cavity face is rapidly decreased to a temperature lowr than a softening temperature range while the mold temperature measured on the cavity face where a compression insertion piece slides is kept in the softening temperature range of resin, and then pressing is released after the temperature has been gradually decreased by an annealing process after all the mold temperatures, are increased up to the softening temperature range of heating. CONSTITUTION:After a primary cooling process, band heaters 29, 30, 31, 45 are turned ON, a stationary type insertion piece 12, stationary type bushing 46, compression insertion piece 18 and movable type bushing 19 are heated and made into the temperature falling within a range of the heat deforming temperature - the heat deforming temperature +40 deg.C. After reheating process of a mold, a mold temperature is kept within the softening temperature range of resin while the resin in the inside of a cavity 1 is being kept at a state wherein shaping of the same based on compression operation is possible. Meantime, pressing based on a hyraulic cylinder 20 is kept on, the mold temperature is gradually decreased down to the heat deformation temperature -20 deg.C at a cooling rate of less than 5 deg.C/min in succession, molding shrinkage of the resin of the inside of the cavity 1 becomes identifiable, similarity shrinkage is realized to the cavity 1 which has been manufactured highly accurately and molding with high dimensional accuracy is performed. |
