Launched in 2017, the recently completed European Union Integrated manufacturing of REcyclable multi-material COmposites for the TRANSport sector (RECOTRANS) project has demonstrated the use of microwaves and laser welding to obtain recyclable composites for automotive and transport applications.

The initiative was designed to produce lighter and, therefore, less polluting vehicles without increasing costs. Researchers from seven nations successfully realized a reduction in costs and energy consumption in New thermoplastic composites were developed through the integration of microwaves and laser welding. Source: RECOTRANSthe manufacture of three prototypes, and confirmed the feasibility of recycling and processing the resulting material.

New thermoplastic composites were developed through the integration of microwaves and laser welding. Microwave systems were effectively used to optimize the curing process of composites in resin transfer molding (RTM) and pultrusion, which reduces the energy consumed, shortens manufacturing times and helps produce better-quality parts. It was also shown that laser technology can be used to obtain stable joints between the composite and metal, thus making it possible to do without riveted joints, which increase structural weight. Finally, studies were conducted on the recyclability of the thermoplastic composite by using it to manufacture a new part.

These results were validated through the manufacture of three life-size demo samples and one demo sample from the recycling material. The demo sample of the rear suspension system of a truck cab was manufactured through the integration of microwaves in the RTM process to make a thermoplastic composite with glass fiber, thermoplastic acrylic resin and a composite-metal joint made using laser welding.

An automotive door panel was also manufactured by integrating microwaves in the RTM process to make a thermoplastic composite with carbon-fiber reinforcement and thermoplastic acrylic resin. An interior panel was manufactured for the rail industry by using microwaves in the pultrusion process to make composites with glass fiber reinforcement and thermoplastic acrylic resin. The joint between the composite and metal parts was made using laser welding.

In addition, the recyclability of the materials was validated by manufacturing a demo sample of a car door handle made of 50% recycled material.