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Injection molds are used to perform injection molding operations using an injection molding machine, and are generally used to produce plastic parts using core and cavity. The molds are classified into two plate molds or three plate molds depending on daylight and mold. The two plate mold requires a single day in light, while the three plate mold requires two days. The mold construction depends on the shape of the component, which determines the parting line selection, runner and gate selection, and component ejection system selection. The mold base size depends on component size and number of cavities to be planned per mold. ==Considerations in Injection Mold Design== * Draft: Required in both the core and cavity for easy ejection of the finished component. * Shrinkage allowance: Depends on shrinkage property of plastic material core and cavity size. * Cooling circuit: In order to optimize the cycle time, water will be circulated through holes drilled in both the core and cavity plates. * Ejection gap: The gap between the ejector plate face and core back plate face should hold dimension within the core. Also, must ensure component is fully removed from the mold. * Air vents: Remove air gases entrapped between core and cavity (usually less than 0.05mm gap), because excessive gaps can result in flash defect in components. * Mold Polishing: The core, cavity, runner and sprue should all have good surface finish and should be polished along material flow direction. * Mold Filling : The gate should be placed such that the component is filled from the thicker section to thinner section. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Injection mold construction」の詳細全文を読む スポンサード リンク
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