Adhesive Bonding of Sheet for Laminated Metal Tooling

There exists a significant body of work on metal laminate tooling built by the “cut-stack-bond” approach; however, automation with this method is difficult. Building laminations by "stack-bond-cut" sequence, on the other hand, is more amenable to automation. Two main challenges of "stack-bond-cut" sequence are blind contour cutting and bonding of the sheet. In this study, we investigate the hot-roller method of thermoplastic adhesive bonding for the metal laminations. Metal sheet, having thermal characteristics significantly different from paper, poses its own specific problems. During the bonding process, in order to achieve good bond strength, appropriate heat and pressure must be applied. As the stack builds up, thermal and mechanical properties change. This inconsistency of process conditions can potentially lead to part warpage, unless carefully controlled. Temperature measurements with a thermocouple embedded into lamination stack showed the effect of bonding process parameters on the laminate temperature.