The main reason of scrap in cold runner system of injection molding is the feeding system which consists of sprue,
runner and gate system. Runner has different cross sections for different applications. In this study, new geometry of
runner system with elliptical cross section in comparison with round cross section was successfully developed for
injecting two circular plates with thickness 1mm. filling time, melt temperature; mold temperature; pressure holding
time and pure cooling time are evaluated as process parameters.
Elliptical cross section in comparison with round cross section which has the highest efficiency among
current geometries of cross section has 25% reduction in scrap and 2.5% in cooling time for injected parts. The
result from simulation demonstrates that the elliptical cross sectional shape of runner is an effective geometry to
reduce the scrap and total cycle time and also the easy ejection of molded part out of the cavity. It demonstrates the
robustness of new geometry of runner system. Further than our anticipation, remarkable phenomena was detected
which is related to process parameters and new geometry of runner system that will be discussed in another paper.
The experimental set up will be conducted to justify the simulation result.