Sheet metal bending with flexible tools

New technological opportunities and the recent needs of the market, which evolves towards mass customization, create a growing interest on the use of additive technologies (3D printing) to add flexibility on the production geometries and reduce tooling costs. In the sheet-metal bending manufacturing sector, rigid metallic tools are the most commonly used. This article presents recent findings in the field of no spring ban-metal tools for bending. This type of tool ensures long term performance but has limitations on adaptability to specific geometries and implies high production costs. Over the years, unfilled or reinforced plastic materials have often been considered a lightweight and cost-efficient alternative for replacement of metal mechanical parts. The use of polymeric materials can offer cost and time reduction by including new architectures to allow the integration of additive and subtractive production technologies. Furthermore, unfilled thermoplastics can be recycled at the end of the process. The introduction of equipment combining a metallic support base and a polymeric die insert with sufficient strength is proposed as a solution to reach high performances using non-conventional materials. The polymeric die insert may be produced by 3D printing or other rapid manufacturing technologies and it is rapidly changeable. The modular base allows heavy mechanical loads, while the polymeric die reduces the aesthetical defects of the bent sheets. The study shows that, in air bending, polymeric die inserts allow a process capability which is comparable to the capability reached with metal dies.