Combinations of metal and plastics are increasingly being used for lightweight constructions – in the automobile industry, for example. However, connecting the two materials poses a challenge, due to their different physical properties. Adhesives take a long time to harden, while plastics can be easily damaged during riveting.
The Fraunhofer Institute for Material and Beam Technology IWS has now unveiled a new joining gun , which works with the HeatPressCool-Integrative (HPCI) process developed by the institute. First, the metal is pretreated with lasers, to optimize the adhesion between metal and plastic. The two materials are then pressed together with the gun, whereby the metal at the bonding point is subjected to inductively generated heat. This causes the surface of the plastic to melt at exactly this point, which in turn forms a firm bond with the metal as the plastic solidifies.
To help companies seamlessly integrate it in their production processes, the Fraunhofer IWS’s gun has a modular design, enabling it to be mounted on a robot arm in place of a spot welding gun, for example.