| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection-compression molding method which reduces the deterioration in shape precision by the residual strain of a molded article occurring in a compression and cooling process without applying labor in the setting of molding conditions due to trial and error, and a mold in injection-compression molding. SOLUTION: When the resin in the mold immediately after holding pressure is in a liquid phase state, a high compression pressure is applied. From a point of time when the average temperature of a molded article reaches the vicinity of a TC point (phase change point), the relation between the temperature and pressure of the resin is exhibited as a functional formula in such a case that a specific volume is made constant from PVT characteristics being a material physical property value specific to the resin. Similarly, the time change of a resin temperature in a cooling solidification process for the molten resin is calculated from the equation of the pressure and flow rate of the molten resin using a finite-element method by numerical calculation. By calculating the relation between pressure and time from two functional formulae obtaned by setting the average temperature of the molded article to the resin temperature, the time change of the compression pressure of the mold is calculated. The mold is subjected to compression control on the basis of the conditions of the time change of the compression pressure. COPYRIGHT: (C)2004,JPO&NCIPI |
