Carbon-based products and materials manufacturer, SGL Group and chemicals company BASF have concluded the joint research of a new composite material system as an important development step of their collaboration. The system aims at enhancing the cost-effectiveness of manufacturing thermoplastic carbon-fibre composites, for example in injection procedures (T-RTM: thermoplastic resin transfer moulding) and reaction injection moulding. The composite is based on a reactive polyamide system and compatible carbon fibres. A carbon-fibre surface—or sizing—specially designed for the matrix system as well as tailored thermoplastic reactive systems mean that lightweight structural components for, say, the automotive industry can now be manufactured quickly and easily.

This collaboration between the two Germany-headquartered firms was launched back in October 2012. On the basis of the now-complete material research, the transfer of the special systems made from carbon fibres and matrices into specific applications of customers in the automotive industry is now under way.

As part of this collaborative project, SGL developed a new sizing formulation for the carbon fibres. In addition, special processes for manufacturing carbon-fibre-based textiles such as fabrics and braidings were also developed. To produce Non-Crimp-Fabrics (NCF), special threads are used that enable processing in the reactive polyamide system.

BASF's role in this project was to process SGL’s newly developed carbon fibres using the T-RTM technique and to characterise them comprehensively both chemically and mechanically. The BASF research team is continuing to work intensively on the development of caprolactam-based thermoplastic reactive systems.

Tilo Hauke, head of research at SGL, said, "The interaction of all components is of central importance for innovative composites based on reactive polyamide. With its extensive material knowhow, SGL Group brought a range of tailored solutions for sizings and fiber processing to this collaborative project."

Meanwhile, Josef R. Wünsch, Head of Structural Materials and Systems Research at BASF said that BASF’s is working on the development of robust polyamid 6 carbon-fibre composite systems, in close collaboration with plant manufacturers as well as tiers and automotive OEMs/ The mechanical characteristic values arising from the interaction of the fibre and matrix are crucial input parameters for the firm’s simulation tool Ultrasim. “We are currently working intensively on enhancing our simulation expertise for reactive systems so that we can provide our customers with expert support for part design and optimisation,"Wünsch added.

Thermoplastics-based carbon-fibre composites combine the properties of carbon fibres such as high rigidity and low weight with the familiar processing advantages of thermoplastics, allowing them to be formed, recycled and welded. This helps make carbon fibre technology an even more viable proposition for large-scale production in a number of different applications.