Multi-Objective Optimization of Injection-Molded Components for Defect Reduction and Warpage Minimization

Abstract:

Warpage in injection-molded thin-walled box-shaped parts is primarily caused by non-uniform cooling and differential shrinkage. This study proposes a two-step, multi-objective optimization strategy to reduce part warpage by addressing both thermal and geometric factors. In the first step, the mold cooling system is optimized through a bi-objective formulation that simultaneously minimizes (i) the temperature standard deviation within the part and (ii) the total cooling channel length. The optimization is carried out using a coupled workflow involving parametric CAD modeling, Autodesk Moldflow simulations, and a genetic algorithm. The optimized cooling design reduces temperature non-uniformity by 44% compared to a conventional cooling layout. In the second step, a geometric optimization is performed through the addition of a reinforcing border, where maximum deflection and total part volume are minimized simultaneously. The combined optimization leads to a reduction in maximum warpage from 14.5 mm in the reference configuration to 2.06 mm in the final design. The results demonstrate the effectiveness of a sequential optimization approach in achieving significant warpage reduction while maintaining material and manufacturing efficiency.

• Periodical: Defect and Diffusion Forum (Volume 451)
• Pages: 133-146
• DOI: https://doi.org/10.4028/p-jEnO27
• Online since: April 2026
• Authors: Keltoum Oubellaouch*, Riccardo Pelaccia, Giulia Zaniboni, Vincenzina Siciliani, Barbara Reggiani
• Keywords: Injection Moulding, Numerical Simulation, Optimization, Warpage Reduction

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