PLANNING OF SHAPE OF BLOW MOLDED BOTTLE BY BLOW MOLDING ANALYSIS

摘要

PURPOSE: To judge the proper range of the total height or shoulder part diameter of a molded bottle by dividing the shape of a preform and that of a blow mold into minute elements and imparting definite initial temp. distribution and blow pressure to perform numerical analysis and graphically displaying functions having the max. and min. wall thicknesses of all elements and the total height or shoulder part diameter of the bottle as variables. ;CONSTITUTION: The shape model of a blow mold and that of a preform or parison are divided into elements and a finite-element method is adapted. The initial temp. distribution and blow pressure optimum to the preform and the mold are inputted and blow molding analysis due to structural analysis-heat conductivity analysis-contact heat transfer analysis perfect coupled analysis is performed. The total height (h) or shoulder part diameter (d) of a bottle is changed with respect to the shape of one kind of preform to perform analytical operation and the total height (h) or shoulder part diameter (d) of the bottle is set to variables with respect to the max. and min. thciknesses θmax, θmin in the wall thickness direction obtained with respect to all elements to calculate formula I-IV to graphically display them. The range of the proper total height or shoulder part diameter of the bottle is evaluated and judged with respect to a predetermined preform or parison.;COPYRIGHT: (C)1995,JPO