Inline functionalization of pultrusion profiles

The FunPul research project demonstrated how the pultrusion process can be extended to enable the cost‑effective manufacturing of highly complex lightweight structures with integrated sensory and mechanical functions, as well as multiaxial fiber reinforcements.

Key project results

1. Bridge sensor with integrated strain measurement
   Manufactured inline during the pultrusion process, this sensor enables precise and continuous component monitoring for wind turbines. A previously handcrafted structure was successfully transformed into a reproducible and industrially viable series production process.
2. Functionally integrated profiles with metallic functional layer
   The metallic layer, embedded in the top surface of the profile as a part of the manufacturing process, provides improved force transmission and enhanced connection options while protecting the FRP structure. This approach significantly expands the application potential of pultruded profiles by enabling alternative joining methods.
3. Complex multi‑chamber hollow profile
   Implemented as an application‑oriented demonstrator for rail vehicle construction, this multi‑axially reinforced profile illustrates the potential of pultruded structures to replace conventional extruded aluminium profiles, while reducing weight and enabling functional integration.

Fraunhofer IWU developed the key components required for this purpose, including

• modified tooling and impregnation concepts,
• feeding and peripheral systems for sensors and metallic elements,
• process‑integrated simulations (“digital twin”), and
• the complete implementation of the demonstrators in a real pultrusion process.

FunPul demonstrated that pultrusion today can achieve far more than the production of conventional FRP profiles: it enables multifunctional, intelligent, and application‑oriented lightweight structures that can be manufactured economically in series.