Inspection, repair and remanufacturing (Use-case 3)
for End-of-Life CFRP products in high-tech applications
Input sector: EoL CFRP from automotive.
Output sector: automotive.
Materials and technologies: CFRP, non-destructive inspection techniques, laser cutting and repair, adaptive design and CAM/CAD techniques.
Motivation and concept for remanufacturing and reuse: CFRP composites were recently introduced into the series production of automotive car bodies as these materials enable higher levels of lightweight construction. With the use of fiber composites, recycling gets more challenging. However carbon fiber composites show some beneficial features which open new opportunities regarding the circular economy. Compared to metal parts, the degradation of composite parts proceed relatively slowly. The reasons are the intrinsically high corrosion resistance and the remarkable fatigue behavior. Thus at the end of a car’s product life the mechanical properties of the EoL CFRP structures are still close to new parts. Considering that, remanufacturing and reuse of CFRP structures gain more and more attention from automotive companies. With the reuse of whole parts and assemblies, sustainability and resource efficiency would be significantly improved with remarkable economic benefits. But the extended use of composite structures is in conflict with frequent design changes in the automotive industry. There are two approaches to solve this problem:
- Remanufacturing of the whole body-in-white (BIW), realization of design changes only by means of mounting parts (Approach 1)
- Disassembly of the EoL BIW, remanufacturing and adapting of composite parts for use in a new body-in-white (Approach 2)
The remanufacturing of the whole BIW is in general a cheaper, quicker and more ecological reuse approach. But the challenge will be to keep up the attractiveness of the total car design. The designer’s scope for modifications would be restricted to mounted parts like non-structural cover parts and exterior elements (face-lift).
Larger design changes will be enabled by means of a modular construction system which allows to build-up different bodies-in-white using a manageable range of composite structures. As design changes are important for the automotive business, this project will mainly focus on the second approach (Approach 2).
A graphical representation of new circular economy case that will be realized in the use-case 3 is shown below. To show the feasibility and to generate data for later business plans, two specific demo-cases and end-use applications will be implemented, as follows:
Demo-case 1: design and remanufacturing of a CFRP chassis component.
Demo-case 2: design and remanufacturing of inner body car structure with refurbished CFRP.
To demonstrate the remanufacturing potential for BIW parts (demo-case 1), a B-pillar will be the main target. On the other hand, the inner car structure that wll be developed in demo-case 2 is represented by a rear seatback structure from reused CFRP. The remanufactured structures should fulfill the new or original requirements for stiffness and fatigue strength depending on the function of the new part, matching approximately half of the price of the new part.
The main challenges of Use-case 3 will be:
- Development of a modular, composite adapted and reuse-oriented BIW concept. Such concept will comprise structural standard elements which can either be realized with new parts or with reused parts.
- Quick and non-destructive disassembly of EoL car bodies. Composite parts have to be separated for inspection, refurbishment and reuse. Detachable joints (i.e. detachable adhesive joints) are required which can be released without damaging the composite structure.
- Non-destructive testing and repair. For the inspection and remanufacturing of used parts, quick, reliable and efficient technologies are required. Furthermore innovative repair solutions are needed to compensate smaller damages.
- Appropriate business concepts which support the global collection and refurbishment of used parts have to be identified. With that, European start-up activities for a circular economy shall be prepared.
