on 10/23/2020





Project Name: Optimization of Warpage of Director in Vehicle Seat Belt

School: Shantou University
By Xiaodong Niu, Juntao Cheng, Yihui Zhang, Bin Chen



The vehicle driving safety has always been a subject of concern and the safety of the vehicle seat is closely related to the safety of drivers and passengers in the vehicle. The safety buckle of the vehicle seat is one of the important safety components of the vehicle.  The precision of its dimension is required for successful assembly with other safety components.  Its dimension needs to be strictly controlled, otherwise, it will cause problem such as dimension deformation and result in an unqualified product. In addition, the mass production of the safety buckle requires longer cooling time to ensure the dimensional precision which results in low production efficiency. The Ray-Bonus team used Moldex3D molding analysis software to position the hot spot of the product and conduct the optimization of design for a conformal cooling channel to successfully improve product quality and enhance production efficiency.


  • Improve the appearance flaws such as sink mark and volume shrinkage
  • Reduce the warpage and fulfill the requirement of dimension
  • Shorten the cooling time and improve production efficiency



After verifying the hot spot of the product with the injection simulation analysis, we conducted systematic optimization analysis by combining three approaches such as experimental design, conformal cooling design, and pre-deformation design, so that the heat can be evenly and rapidly dissipated in the molding process of the product to reduce warpage, shorten the cooling time and effectively enhance the production efficiency.  




  • We successfully controlled the warpage of the director in the rage of ±0. 5 mm which meets the requirement of dimensional precision for the product
  • The factors that significantly affect the warpage of the director are selected through simulation, and the parameters of the process are optimized to reduce the warpage by 64%
  • The time for cooling the product to the ejection temperature is reduced by about 40%, which speeds up the solidification process and reduces the risk of warpage


Products Used

Meet the Team

We would like to thank CoreTech System Co. , Ltd.  for organizing this molding competition, which provides a very good learning and communication platform for us so that we have the opportunity to demonstrate our work and share it with everyone. We would also like to thank Ruibonasi Additive Manufacturing Research Institute Co. , Ltd.  and Ruixiang Molding Co. , Ltd.  for their strong support so that we can combine simulation and reality through the utilization of molding analysis. Lastly, we would like to thank the members of the team for their efforts and dedication to improving and completing this project.  We continue to put in more effort! Thanks again to CoreTech System Co. , Ltd.  for hosting this contest and recognition of our work.


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