Proposal to reduce the time in the manufacture of soft tooling using the additive manufacturing process

摘要

The development of cold stamped steel parts begins with the production of prototypes for validation of assemblability. In this phase, a reduced quantity of parts is requested, using simplified tooling known as soft tooling (ST). For the manufacture of this tool, special steels are used, which have a high cost. In addition, its average construction time can be up to 1 month, a relatively high period considering the dynamism required at this stage of designing a new product. In this scenario, the present work proposes the construction of a polymeric tooling using the additive manufacturing (AM) technique, commonly known as “three-dimensional (3D) printing”, aiming a considerable reduction of costs and manufacturing time. For this, a 3D Makerbot Z18 printer with a useful volume of 305 × 305 × 457 mm~3 and Polylactic Acid (PLA) filaments was used. The tooling was printed as a beehive, followed by full filling with epoxy resin to increase the compressive strength. The format defined for the tooling was a spherical cap with a radius of 25 mm, aiming to simulate the production of parts via deep stamping, which represents a severe stamping condition. The results showed a reduction of 80% in tooling manufacturing time. Furthermore, the tooling allowed the stamping of 6 parts of GMW3032M-ST-S-CR270B2 steel with a thickness of 1.00 mm, where 4 parts showing dimensional stability. The durability and stability of ST allowed production of prototypes for the first evaluations, showing how promising the strategy of developing prototypes using tooling manufactured in 3D printer.