Blow molding is one of the most important forming processes for producing complex thermoplastic industrial parts. During these processes, residual stresses caused by inhomogeneous cooling and relaxation of polymer chains, often result in shrinkage and warpage of the final part. Tolerance issues are critical in many extrusion blow molding applications, and therefore part deformation due to solidification needs to be controlled and optimized according to specific design criteria. Part designers in today's global environment are under increasing pressure to reduce part development time to a minimum, yet ensuring the maximum part quality and minimum manufacturing costs. If the dimensional changes of a part can be estimated before a tool is built, the design engineer gets a valuable tool to avoid costly and expensive modifications to the mold. Therefore, the development of an accurate simulation tool, well suited for industrial applications, to predict thermoplastic part deformations due to solidification, has become essential for designers to help achieve an efficient production.
The aim of this work is to show the latest advancements in predicting solidification and warpage of Plastic Fuel Tanks using NRC's BlowView software. The numerical warpage simulation results obtained using BlowView will be presented based on an industrial case study. The importance of using the ideal geometry and a uniform mesh representing the mold cavity to perform the warpage analysis, rather than the distorted inflated parison mesh, will be highlighted. The simulation results, in terms of displacements, are also compared to the actual scanned part using the best fit technique in order to exemplify the accuracy and reliability of the proposed approach.