Injection molded parts often have small complex features so the construction of models is usually the most time-consuming aspect of model analysis.
It is not always necessary to create a complete model. Simplifications that save modeling and analysis time can often be made. The fundamental principle is that the model must be equivalent to the flow in the real part. Flow is dictated by the following elements, listed according to their significance.
The aim should therefore be to create a model with the same thickness, flow length and volume as the real part. When good practices are observed, a simple model will generally provide similar results to a more complex model of the same part.
There are three distinct processing phases in injection molding.
Cycle time is the total time required to complete all the stages of the injection molding cycle.
Molten plastic will preferentially flow through thicker sections of a mold, but subtle changes to the part geometry can help to balance the flow.
Some mold surfaces must be tapered so that the plastic part can be ejected from the mold when it has cooled sufficiently.