The injection time referred to here is the time required for the plastic melt to fill the mold cavity; it excludes auxiliary times such as mold opening and closing. Although the injection time is very short and has a minimal impact on the overall molding cycle, adjusting it plays a significant role in controlling pressure within the gate, runners, and cavity. An appropriate injection time facilitates ideal melt filling and is crucial for enhancing the product's surface quality and minimizing dimensional tolerances.
Injection time is significantly shorter than cooling time-typically one-tenth to one-fifteenth of the latter-a ratio that can serve as a basis for estimating the total molding time for a plastic part. In mold flow analysis, the injection time in the results matches the setting defined in the process parameters only when the cavity is filled entirely through the screw's rotational drive. If the system switches to the holding pressure phase before the cavity is fully filled, the analyzed injection time will exceed the process setting.
