Usually when connecting metal and plastic objects using glue or rivets. However, these methods have their drawbacks: the bonding surfaces must be some time left alone, so the glue “grabbed”, which slows the production process, as the rivets can damage the plastic surface. In addition, when mass production always requires a large number of such connective material.
Engineers Institute of materials and beam technology Fraunhofer (Germany) have developed a device that connects these components quickly and simply, through a process called HeatPressCool-Integrative (HPCI).
First, a metal and plastic object is compressed in the place of the future connection. Then metal shall be spot induction heating, which in turn leads to a partial meltdown of plastic. While its surface layer is molded into an array of tiny anchor structures that have previously been laser engraved on the metal surface in the junction.
During hardening the plastic shrinks and forms a solid connection between the two structures. It is very important that the whole process lasts only a few seconds.
Specialists of the Institute are convinced that they have developed a device based on the technology of HPCI will find application in existing production lines — for example, in robotic manipulators, replacing the spot welding guns.
Source — Fraunhofer