To enable cost-effective assembly and repair of thermoplastic sandwich components in small- to medium-scale production, new joining technologies must be developed. The Fraunhofer Institute for Microstructure of Materials and Systems IMWS is collaborating with the SKZ Plastics Center and other partners on the “Thermoplastic Sandwich Construction Elements (TheSaKo)” project to deliver lightweight, cost-efficient, and recyclable solutions, supported by demonstrators and technology transfer activities tailored for SMEs across industrial sectors.
Conventional joining methods are often designed for thermoset sandwich structures and typically rely on mechanical fasteners, resulting in longer manufacturing cycle times and limited recyclability. While joining approaches for thermoplastic sandwich structures—such as welding and bonding—offer clear advantages, they require tailored, load-specific joint designs and precise process control, particularly when applied to large-area components.
TheSaKo project partners plan to provide cost-effective use of thermoplastic sandwich components in small to medium-volume production through:
- Developing deformable joining surfaces directly during the manufacturing process (thermoforming)
- Adapting welding and bonding technologies to these surfaces
- Lower material and joining element costs, moderate costs for adhesives and surface treatment
- Integration of repair concepts that withstand moisture and temperature cycles and keep recycling pathways open, to extend product lifespan
- Demonstrators for modular large-scale structures and localized functionalization.
“Together, we want to make it possible to economically join and repair thermoplastic sandwich structures in small to medium-sized production runs – this makes lightweight construction a concrete reality in the SME sector,” says Dr.-Ing. Ralf Schlimper, project manager at Fraunhofer IMWS.
“By combining thermoformable joining surfaces, adapted joining technologies, and repair-friendly concepts, we are building a bridge from basic research to industrial practice – including recyclability and cost-efficiency,” emphasizes Michael Heilig, project manager at SKZ.
