The connection of plastics and metals poses a challenge due to the different physical properties of the two materials. All conventional joining options, such as bonds using adhesives or rivets, have their disadvantages — adhesives need time to harden, which delays further processing, and plastics can be easily damaged during riveting. Furthermore, both adhesive bonding and riveting require additional materials that increase production costs.

The joining gun bonds metal and plastic in seconds and can be mounted on a robot arm in place of a spot welding gun. (© Fraunhofer IWS)

A joining gun was developed that creates a connection between metal and thermoplastic materials within seconds. A HeatPressCool-Integrative process is integrated into the joining gun, enabling the direct and precise bonding between metal and plastic components. During this process, the two materials are pressed together and the metal at the bonding point is subjected to targeted inductive heat. This causes the thermoplastic material to partially melt, which in turn directly forms a firm bond with the metal as the plastic solidifies.

The metal is pretreated with lasers to optimize the adhesion between metal and plastic to create anchoring structures. Laser ablation is used to drill into the metal to a depth of up to 100 micrometers, where the plastic can penetrate and then cool down and contract to form a secure fit in the structure.

A modular structure enables the joining gun to be integrated into existing system technology in manufacturing operations; for example, it can be mounted on a robot arm in place of a spot welding gun. The joining gun can be applied wherever metal and plastics need to be precisely bonded.

For more information, contact Markus Forytta at +49 351 83391-3614 or visit here.