| 摘要 |
PURPOSE:To obtain a molded product free from deformation, a shrink mark cavity, air bubbles and the irregularity of dimensional preciseness caused by residual stress, by respectively performing the program controls of a filling process and a pressure holding process according to a method suitable for a molding process. CONSTITUTION:A filling process is completed by passing a screw through A-E sections at injection speeds V1-V5 and pressure to be held is changed to holding pressure P3 from holding pressure R2 in a pressure holding process. When the surface part of a cavity is held under a sufficient flowable state, the holding pressure is made low to prevent the generation of a burr and, when a skin layer is properly cooled, high pressure P3 is applied to prepare a molded product free from a shrink mark. In this case, residual stress can be reduced by lowering pressure corresponding to a cooling progress state. |
