Research conducted collaboratively by SimpaTec, Premec S.p.A., Toolax, and Contura MTC revealed how the team used Moldex3D to find out a cost-effective method to yield a high-gloss surface finish. In their study, they simulated the injection molding process under conventional thermal and variothermal control using the same injection mold with conformal cooling. In addition, two materials — PC+ABS and PA6-GF30 — were analyzed in this research.
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The simulations of the shear stresses (bottom) and real parts made under conventional thermal control (top left) and variothermal control (top right). (Photo Credit: SimpaTec) |
In the Case of the PC+ABS Reference Part
Both variothermal control and conventional thermal control could produce an ideal piano-black finish. The reference part of the former was free of streaks, weld lines, and similar defects. This was because the temperature is still so high that the weld lines are less pronounced on the variothermally-controlled side of the part. In contrast, with conventional temperature control, the process may initially yield a streak-free finish, but visible weld lines still could be detected on closer inspection. Thus, a downstream coating process was required, potentially leading to an increase in overall cost and energy consumption.
In the Case of the PA6-GF30 Reference Part
The team revealed that it was difficult for parts made from PA6 with 30% glass fiber to achieve a glossy fiber finish without any coating. They analyzed the maximum shear stresses at the end of the filling phase in the two variants. Under conventional thermal control, the gradients of the shear stress suggested a non-uniform part surface. On the other hand, the less-pronounced shear stress gradients in the variothermal simulation could result in a higher quality surface, and yet a downstream coating process might still be needed. With these findings, the team showed the feasibility of predicting the quality of the real part’s surface through the shear stress simulation.
The Use of Process Simulation Matters
The team used Moldex3D to analyze important data such as the shear stresses and the temperatures of the weld lines, making it possible to predict the quality of the surface finish at the early design stage and to estimate the cost and energy requirements. For a better interpretation of important processing parameters, making the most of process simulation counts and it also makes comparing different projects a lot easier.
