A team of researchers at the Fraunhofer Institute for Material and Beam Technology have created a joining gun. This gun establishes a connection between metal and thermoplastic materials in a few seconds. It has a modular design and can be incorporated into the production process. For example, the production of the gun in the assembly replaces the spot welding gun if mounted on a robot arm. A scientist named Annett Klotzbach at the Hanover Trade Fair demonstrated the advantages of the joining gun.

The Heat Press Cool-Integrative process HPCI

The connection between metals and plastics poses a challenge because of difference in physical properties of the two. All standard attachment options, like bonds using adhesives or rivets have drawbacks, these adhesive need time to harden leading to delay in further processing. At the time of riveting plastics are prone to damage. Moreover, riveting and adhesive bonding both requires additional matter leading to increased production costs.

More stable connection by pre-treatment of the metal

To address the limitations of metal, scientists at Fraunhofer IWS pretreated the metal with lasers to improve the adhesion between plastic and metal, to create anchors. One of the researchers, Annett Klotzbach said that the process has a unique feature where laser ablation is used to drill deep into the metal. This laser will drill to a depth of about a hundred micrometers. The depth is sufficient to penetrate into the metal, contract and form a secure bond with the structure. This establishes an extremely stable bond.

Easy application in proven system technology

The joining gun gives a modular structure, to the current technology in manufacturing operations. It can be applied wherever plastics and metal need to be bonded specifically, such as for the construction of vehicle’s body parts.