Two German universities join hands to carry out research into a combined process that involves the deep-drawing of metal and its backmolding with plastic for the production of hybrid plastic/metal structural parts.
The two parties involved are the Institute of Forming Technology and Lightweight Construction (IUL) at the Technical University of Dortmund , and the Institute of Plastics Processing (IKV) in Industry and the Skilled Crafts at RWTH Aachen University.
The plastic serves to increase the stiffness, and may also contain functional and/or fixing elements. One requirement for the reliable production of such hybrid parts is a suitable bonding agent, which is first applied to the steel component. This provides a cohesive bond that ensures a homogeneous stress profile in the hybrid part.
This combined process makes use of the closing motion of the injection molding tool to form the metal sheet, because the kinematics of an injection molding tool are similar to those of a deep-drawing die, explained IKV Aachen.
This saves a complete process step. A metal insert is first formed by deep-drawing during the integrated process and is subsequently further molded into shape with the plastic melt.
At the heart of the process is the combined tooling technology which brings together the elements of the deep-drawing die with those of the injection molding tool. The drawing punch and draw die are the forming elements here.
A clamping mechanism controlled independently of the injection molding machine’s clamping unit provides for controlled passage of the steel sheet and prevents any creasing on the deep-drawn part.
The combined injection molding tool was made by Herrmann Rausch Formenbau in Germany, and is available with immediate effect to the project partners IUL and IKV for their studies of the combined process.
The systematic analysis of the combined process is being funded via the AiF as part of Joint Industrial Research (IGF) by Germany’s Federal Ministry for Economic Affairs and Energy (BMWi).