In this study, the generation of flash and the mold deformation were investigated when molding conditions were varied in a slide core type mold for molding cylindrical products. When a gap was formed at the divided face between slide cores, how it would influence on generation of flash and mold strain was also investigated. Based on the results, the following results were obtained.
A universal correlation was found between the generation of flash and mold deformation regardless of the injection rate, cylinder temperature, and type of resin used, and even with complicated generation of flash where primary flash and secondary flash occur continuously. In addition, it was confirmed that when gaps are formed at the divided face between slide cores, primary flash occurs due to the flow of melt into the gap even at low holding pressures, and even if primary flash occurs, the outputs of mold strain sensors do not change.

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