In the injection molding process, the complete production cycle will go through filling, packing, cooling, mold opening, and ejecting. During the time of mold opening after cooling, the part surface at the core side contacts the mold and the surface at the cavity side contacts air. It causes unsymmetrical heat transfer between the two surfaces which constrains the mold at the core side when the part shrinks.

Now, Moldex3D can support the cooling calculation during the time before and after the ejection. Considering the status of the part during this time can make the simulation more consistent with reality. The operation steps are shown below.

1. Solid Cooling Simulation Considers Cooling Effect Between Mold Opening and Ejection Procedure

Step 1 Prepare a mesh model with the mold plate, set the attributes as Mold Plate (Fixed) and Mold Plate (Movable), and then generate the mesh.

Note: Non-matching mesh is supported.

Step 2 Open the Moldex3D Process Wizard. In the Cooling Setting, set Ejection Timing After Mold Open, and the time should be smaller than the Mold-Open Time.

Step 3 Open the Computation Parameter. In Warpage, the solver should be changed from Standard to Enhanced (to have this effect considered in Warpage simulation).

Step 4 In Analysis, the analysis sequence should be Transient Analysis 3 – Ct F P Ct W.

Note: The analysis Log (*.lgc) file will record the settings which are on if all the settings are correct.

2. Result

In the cooling result, the temperature is greatly different between the core side and cavity side because of different contact conditions during the mold opening and ejection time. Measuring the temperature between the core side and cavity side, we can find the temperature difference of the mold plate setting is higher when considering the mold opening before ejection in comparison with the case of without considering. The average temperature difference is 20.4  with the effect considered, while the average temperature difference is only 2.8  with the effect is not considered.

Also, the warpage is affected by the temperature difference. There is an 11.6% difference between the two settings.

	Considering cooling during the time between mold opening and ejection	Without considering cooling during the time between mold opening and ejection
Cavity Side Temperature
Core Side Temperature

Considering cooling during the time between mold opening and ejection	Without considering cooling during the time between mold opening and ejection
Total Displacement：1.413 mm	Total Displacement：1.598 mm