Manufacturing and performance of 3D printed plastic tools for air bending applications

In the sheet metal forming industry, rapid tools, especially those made of polymeric materials, are increasingly used for small to medium volume productions, to compress the times and costs of tooling. The present work is aimed at evaluating the performance of 3D printed tools for sheet metal V-die air bending process. Samples made of polycarbonate and polylactide were characterized through compression tests, using different printing strategies, to verify the effect of the printing parameters on the strength of the materials. FEA simulations of air bending were performed in order to predict the state of stress and strain of the plastic tools. Polymeric dies were then produced and used for repeated V-bending tests of metal sheets. The endurance and performance of the 3D printed tools were evaluated by analysing the changes in their surface and the repeatability of the bending angle after springback. The results show how the polymeric materials and their printing parameters influence the performance of the polymeric tools. Among the various tested configurations, the PLA dies, printed with a printing pattern of 45-90-45 degrees exhibit the best performance.